Add a command to change message format while running.

7 files changed, 1021 insertions, 85 deletions

diff --git a/README.md b/README.md
index daed2935..719fb0e8 100644
--- a/README.md
+++ b/README.md
@@ -328,6 +328,28 @@ changed.
 
     { "command_response": "af_bypass", "status": true}
 
+#### Message Format Control
+
+The `message_format` command determines the format for output data from the VI
+and also the expected format of commands sent to the VI.
+
+Valid formats are `json` and `binary`.
+
+**Request**
+
+    { "command": "message_format",
+      "bus": 1,
+      "format": "json"
+    }
+
+**Response**
+
+If the format was changed successfully, the `status` in the response will be
+`true`. The response will be in the new message format.
+
+    { "command_response": "message_format", "status": true}
+
+
 ### Trace File Format
 
 An OpenXC vehicle trace file is a plaintext file that contains JSON objects,
diff --git a/gen/cpp/openxc.pb b/gen/cpp/openxc.pb
index c4000c36..dfad822b 100644
--- a/gen/cpp/openxc.pb
+++ b/gen/cpp/openxc.pb
@@ -1,5 +1,5 @@
 
-Á
+œ
 openxc.protoopenxc"”
 VehicleMessage)
 type
 
(2.openxc.VehicleMessage.Type'
@@ -21,19 +21,21 @@ RawMessage
 bus
 
(
 
 message_id 
(

-data 
("ö
+data 
("È
 ControlCommand)
 type
 
(2.openxc.ControlCommand.Type<
 diagnostic_request 
(2 .openxc.DiagnosticControlCommandG
 passthrough_mode_request 
(2%.openxc.PassthroughModeControlCommandO
- acceptance_filter_bypass_command 
(2%.openxc.AcceptanceFilterBypassCommand"a
+ acceptance_filter_bypass_command 
(2%.openxc.AcceptanceFilterBypassCommand<
+message_format_command 
(2.openxc.MessageFormatCommand"u
 Type
 VERSION


 	DEVICE_ID
 
 DIAGNOSTIC
 PASSTHROUGH
-ACCEPTANCE_FILTER_BYPASS"ž

+ACCEPTANCE_FILTER_BYPASS
+MESSAGE_FORMAT"ž

 DiagnosticControlCommand*
 request
 
(2.openxc.DiagnosticRequest7
 action 
(2'.openxc.DiagnosticControlCommand.Action"
@@ -46,7 +48,14 @@ DIAGNOSTIC
 enabled 
("<
 AcceptanceFilterBypassCommand
 bus
 
(
-bypass 
("]
+bypass 
("†

+MessageFormatCommand
+bus
 
(:
+format 
(2*.openxc.MessageFormatCommand.MessageFormat"%
+
MessageFormat
+JSON

+
+BINARY"]
 CommandResponse)
 type
 
(2.openxc.ControlCommand.Type
 message 
(	
diff --git a/gen/cpp/openxc.pb.c b/gen/cpp/openxc.pb.c
index 39c6a348..3fd1b4ab 100644
--- a/gen/cpp/openxc.pb.c
+++ b/gen/cpp/openxc.pb.c
@@ -1,5 +1,5 @@
 /* Automatically generated nanopb constant definitions */
-/* Generated by nanopb-0.3.1 at Sat Sep 27 19:43:38 2014. */
+/* Generated by nanopb-0.3.1 at Sat Sep 27 19:56:19 2014. */
 
 #include "openxc.pb.h"
 
@@ -26,11 +26,12 @@ const pb_field_t openxc_RawMessage_fields[4] = {
     PB_LAST_FIELD
 };
 
-const pb_field_t openxc_ControlCommand_fields[5] = {
+const pb_field_t openxc_ControlCommand_fields[6] = {
     PB_FIELD(  1, ENUM    , OPTIONAL, STATIC  , FIRST, openxc_ControlCommand, type, type, 0),
     PB_FIELD(  2, MESSAGE , OPTIONAL, STATIC  , OTHER, openxc_ControlCommand, diagnostic_request, type, &openxc_DiagnosticControlCommand_fields),
     PB_FIELD(  3, MESSAGE , OPTIONAL, STATIC  , OTHER, openxc_ControlCommand, passthrough_mode_request, diagnostic_request, &openxc_PassthroughModeControlCommand_fields),
     PB_FIELD(  4, MESSAGE , OPTIONAL, STATIC  , OTHER, openxc_ControlCommand, acceptance_filter_bypass_command, passthrough_mode_request, &openxc_AcceptanceFilterBypassCommand_fields),
+    PB_FIELD(  5, MESSAGE , OPTIONAL, STATIC  , OTHER, openxc_ControlCommand, message_format_command, acceptance_filter_bypass_command, &openxc_MessageFormatCommand_fields),
     PB_LAST_FIELD
 };
 
@@ -52,6 +53,12 @@ const pb_field_t openxc_AcceptanceFilterBypassCommand_fields[3] = {
     PB_LAST_FIELD
 };
 
+const pb_field_t openxc_MessageFormatCommand_fields[3] = {
+    PB_FIELD(  1, INT32   , OPTIONAL, STATIC  , FIRST, openxc_MessageFormatCommand, bus, bus, 0),
+    PB_FIELD(  2, ENUM    , OPTIONAL, STATIC  , OTHER, openxc_MessageFormatCommand, format, bus, 0),
+    PB_LAST_FIELD
+};
+
 const pb_field_t openxc_CommandResponse_fields[4] = {
     PB_FIELD(  1, ENUM    , OPTIONAL, STATIC  , FIRST, openxc_CommandResponse, type, type, 0),
     PB_FIELD(  2, STRING  , OPTIONAL, STATIC  , OTHER, openxc_CommandResponse, message, type, 0),
@@ -110,7 +117,7 @@ const pb_field_t openxc_TranslatedMessage_fields[5] = {
  * numbers or field sizes that are larger than what can fit in 8 or 16 bit
  * field descriptors.
  */
-PB_STATIC_ASSERT((pb_membersize(openxc_VehicleMessage, raw_message) < 65536 && pb_membersize(openxc_VehicleMessage, translated_message) < 65536 && pb_membersize(openxc_VehicleMessage, diagnostic_response) < 65536 && pb_membersize(openxc_VehicleMessage, control_command) < 65536 && pb_membersize(openxc_VehicleMessage, command_response) < 65536 && pb_membersize(openxc_ControlCommand, diagnostic_request) < 65536 && pb_membersize(openxc_ControlCommand, passthrough_mode_request) < 65536 && pb_membersize(openxc_ControlCommand, acceptance_filter_bypass_command) < 65536 && pb_membersize(openxc_DiagnosticControlCommand, request) < 65536 && pb_membersize(openxc_TranslatedMessage, value) < 65536 && pb_membersize(openxc_TranslatedMessage, event) < 65536), YOU_MUST_DEFINE_PB_FIELD_32BIT_FOR_MESSAGES_openxc_VehicleMessage_openxc_RawMessage_openxc_ControlCommand_openxc_DiagnosticControlCommand_openxc_PassthroughModeControlCommand_openxc_AcceptanceFilterBypassCommand_openxc_CommandResponse_openxc_DiagnosticRequest_openxc_DiagnosticResponse_openxc_DynamicField_openxc_TranslatedMessage)
+PB_STATIC_ASSERT((pb_membersize(openxc_VehicleMessage, raw_message) < 65536 && pb_membersize(openxc_VehicleMessage, translated_message) < 65536 && pb_membersize(openxc_VehicleMessage, diagnostic_response) < 65536 && pb_membersize(openxc_VehicleMessage, control_command) < 65536 && pb_membersize(openxc_VehicleMessage, command_response) < 65536 && pb_membersize(openxc_ControlCommand, diagnostic_request) < 65536 && pb_membersize(openxc_ControlCommand, passthrough_mode_request) < 65536 && pb_membersize(openxc_ControlCommand, acceptance_filter_bypass_command) < 65536 && pb_membersize(openxc_ControlCommand, message_format_command) < 65536 && pb_membersize(openxc_DiagnosticControlCommand, request) < 65536 && pb_membersize(openxc_TranslatedMessage, value) < 65536 && pb_membersize(openxc_TranslatedMessage, event) < 65536), YOU_MUST_DEFINE_PB_FIELD_32BIT_FOR_MESSAGES_openxc_VehicleMessage_openxc_RawMessage_openxc_ControlCommand_openxc_DiagnosticControlCommand_openxc_PassthroughModeControlCommand_openxc_AcceptanceFilterBypassCommand_openxc_MessageFormatCommand_openxc_CommandResponse_openxc_DiagnosticRequest_openxc_DiagnosticResponse_openxc_DynamicField_openxc_TranslatedMessage)
 #endif
 
 #if !defined(PB_FIELD_16BIT) && !defined(PB_FIELD_32BIT)
@@ -121,7 +128,7 @@ PB_STATIC_ASSERT((pb_membersize(openxc_VehicleMessage, raw_message) < 65536 && p
  * numbers or field sizes that are larger than what can fit in the default
  * 8 bit descriptors.
  */
-PB_STATIC_ASSERT((pb_membersize(openxc_VehicleMessage, raw_message) < 256 && pb_membersize(openxc_VehicleMessage, translated_message) < 256 && pb_membersize(openxc_VehicleMessage, diagnostic_response) < 256 && pb_membersize(openxc_VehicleMessage, control_command) < 256 && pb_membersize(openxc_VehicleMessage, command_response) < 256 && pb_membersize(openxc_ControlCommand, diagnostic_request) < 256 && pb_membersize(openxc_ControlCommand, passthrough_mode_request) < 256 && pb_membersize(openxc_ControlCommand, acceptance_filter_bypass_command) < 256 && pb_membersize(openxc_DiagnosticControlCommand, request) < 256 && pb_membersize(openxc_TranslatedMessage, value) < 256 && pb_membersize(openxc_TranslatedMessage, event) < 256), YOU_MUST_DEFINE_PB_FIELD_16BIT_FOR_MESSAGES_openxc_VehicleMessage_openxc_RawMessage_openxc_ControlCommand_openxc_DiagnosticControlCommand_openxc_PassthroughModeControlCommand_openxc_AcceptanceFilterBypassCommand_openxc_CommandResponse_openxc_DiagnosticRequest_openxc_DiagnosticResponse_openxc_DynamicField_openxc_TranslatedMessage)
+PB_STATIC_ASSERT((pb_membersize(openxc_VehicleMessage, raw_message) < 256 && pb_membersize(openxc_VehicleMessage, translated_message) < 256 && pb_membersize(openxc_VehicleMessage, diagnostic_response) < 256 && pb_membersize(openxc_VehicleMessage, control_command) < 256 && pb_membersize(openxc_VehicleMessage, command_response) < 256 && pb_membersize(openxc_ControlCommand, diagnostic_request) < 256 && pb_membersize(openxc_ControlCommand, passthrough_mode_request) < 256 && pb_membersize(openxc_ControlCommand, acceptance_filter_bypass_command) < 256 && pb_membersize(openxc_ControlCommand, message_format_command) < 256 && pb_membersize(openxc_DiagnosticControlCommand, request) < 256 && pb_membersize(openxc_TranslatedMessage, value) < 256 && pb_membersize(openxc_TranslatedMessage, event) < 256), YOU_MUST_DEFINE_PB_FIELD_16BIT_FOR_MESSAGES_openxc_VehicleMessage_openxc_RawMessage_openxc_ControlCommand_openxc_DiagnosticControlCommand_openxc_PassthroughModeControlCommand_openxc_AcceptanceFilterBypassCommand_openxc_MessageFormatCommand_openxc_CommandResponse_openxc_DiagnosticRequest_openxc_DiagnosticResponse_openxc_DynamicField_openxc_TranslatedMessage)
 #endif
 
 
diff --git a/gen/cpp/openxc.pb.h b/gen/cpp/openxc.pb.h
index 85b711d5..792aa935 100644
--- a/gen/cpp/openxc.pb.h
+++ b/gen/cpp/openxc.pb.h
@@ -1,5 +1,5 @@
 /* Automatically generated nanopb header */
-/* Generated by nanopb-0.3.1 at Sat Sep 27 19:43:38 2014. */
+/* Generated by nanopb-0.3.1 at Sat Sep 27 19:56:19 2014. */
 
 #ifndef PB_OPENXC_PB_H_INCLUDED
 #define PB_OPENXC_PB_H_INCLUDED
@@ -27,7 +27,8 @@ typedef enum _openxc_ControlCommand_Type {
     openxc_ControlCommand_Type_DEVICE_ID = 2,
     openxc_ControlCommand_Type_DIAGNOSTIC = 3,
     openxc_ControlCommand_Type_PASSTHROUGH = 4,
-    openxc_ControlCommand_Type_ACCEPTANCE_FILTER_BYPASS = 5
+    openxc_ControlCommand_Type_ACCEPTANCE_FILTER_BYPASS = 5,
+    openxc_ControlCommand_Type_MESSAGE_FORMAT = 6
 } openxc_ControlCommand_Type;
 
 typedef enum _openxc_DiagnosticControlCommand_Action {
@@ -35,6 +36,11 @@ typedef enum _openxc_DiagnosticControlCommand_Action {
     openxc_DiagnosticControlCommand_Action_CANCEL = 2
 } openxc_DiagnosticControlCommand_Action;
 
+typedef enum _openxc_MessageFormatCommand_MessageFormat {
+    openxc_MessageFormatCommand_MessageFormat_JSON = 1,
+    openxc_MessageFormatCommand_MessageFormat_BINARY = 2
+} openxc_MessageFormatCommand_MessageFormat;
+
 typedef enum _openxc_DiagnosticRequest_DecodedType {
     openxc_DiagnosticRequest_DecodedType_NONE = 1,
     openxc_DiagnosticRequest_DecodedType_OBD2 = 2
@@ -127,6 +133,13 @@ typedef struct _openxc_DynamicField {
     bool boolean_value;
 } openxc_DynamicField;
 
+typedef struct _openxc_MessageFormatCommand {
+    bool has_bus;
+    int32_t bus;
+    bool has_format;
+    openxc_MessageFormatCommand_MessageFormat format;
+} openxc_MessageFormatCommand;
+
 typedef struct _openxc_PassthroughModeControlCommand {
     bool has_bus;
     int32_t bus;
@@ -172,6 +185,8 @@ typedef struct _openxc_ControlCommand {
     openxc_PassthroughModeControlCommand passthrough_mode_request;
     bool has_acceptance_filter_bypass_command;
     openxc_AcceptanceFilterBypassCommand acceptance_filter_bypass_command;
+    bool has_message_format_command;
+    openxc_MessageFormatCommand message_format_command;
 } openxc_ControlCommand;
 
 typedef struct _openxc_VehicleMessage {
@@ -194,10 +209,11 @@ typedef struct _openxc_VehicleMessage {
 /* Initializer values for message structs */
 #define openxc_VehicleMessage_init_default       {false, (openxc_VehicleMessage_Type)0, false, openxc_RawMessage_init_default, false, openxc_TranslatedMessage_init_default, false, openxc_DiagnosticResponse_init_default, false, openxc_ControlCommand_init_default, false, openxc_CommandResponse_init_default}
 #define openxc_RawMessage_init_default           {false, 0, false, 0, false, {0, {0}}}
-#define openxc_ControlCommand_init_default       {false, (openxc_ControlCommand_Type)0, false, openxc_DiagnosticControlCommand_init_default, false, openxc_PassthroughModeControlCommand_init_default, false, openxc_AcceptanceFilterBypassCommand_init_default}
+#define openxc_ControlCommand_init_default       {false, (openxc_ControlCommand_Type)0, false, openxc_DiagnosticControlCommand_init_default, false, openxc_PassthroughModeControlCommand_init_default, false, openxc_AcceptanceFilterBypassCommand_init_default, false, openxc_MessageFormatCommand_init_default}
 #define openxc_DiagnosticControlCommand_init_default {false, openxc_DiagnosticRequest_init_default, false, (openxc_DiagnosticControlCommand_Action)0}
 #define openxc_PassthroughModeControlCommand_init_default {false, 0, false, 0}
 #define openxc_AcceptanceFilterBypassCommand_init_default {false, 0, false, 0}
+#define openxc_MessageFormatCommand_init_default {false, 0, false, (openxc_MessageFormatCommand_MessageFormat)0}
 #define openxc_CommandResponse_init_default      {false, (openxc_ControlCommand_Type)0, false, "", false, 0}
 #define openxc_DiagnosticRequest_init_default    {false, 0, false, 0, false, 0, false, 0, false, {0, {0}}, false, 0, false, 0, false, "", false, (openxc_DiagnosticRequest_DecodedType)0}
 #define openxc_DiagnosticResponse_init_default   {false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, {0, {0}}, false, 0}
@@ -205,10 +221,11 @@ typedef struct _openxc_VehicleMessage {
 #define openxc_TranslatedMessage_init_default    {false, (openxc_TranslatedMessage_Type)0, false, "", false, openxc_DynamicField_init_default, false, openxc_DynamicField_init_default}
 #define openxc_VehicleMessage_init_zero          {false, (openxc_VehicleMessage_Type)0, false, openxc_RawMessage_init_zero, false, openxc_TranslatedMessage_init_zero, false, openxc_DiagnosticResponse_init_zero, false, openxc_ControlCommand_init_zero, false, openxc_CommandResponse_init_zero}
 #define openxc_RawMessage_init_zero              {false, 0, false, 0, false, {0, {0}}}
-#define openxc_ControlCommand_init_zero          {false, (openxc_ControlCommand_Type)0, false, openxc_DiagnosticControlCommand_init_zero, false, openxc_PassthroughModeControlCommand_init_zero, false, openxc_AcceptanceFilterBypassCommand_init_zero}
+#define openxc_ControlCommand_init_zero          {false, (openxc_ControlCommand_Type)0, false, openxc_DiagnosticControlCommand_init_zero, false, openxc_PassthroughModeControlCommand_init_zero, false, openxc_AcceptanceFilterBypassCommand_init_zero, false, openxc_MessageFormatCommand_init_zero}
 #define openxc_DiagnosticControlCommand_init_zero {false, openxc_DiagnosticRequest_init_zero, false, (openxc_DiagnosticControlCommand_Action)0}
 #define openxc_PassthroughModeControlCommand_init_zero {false, 0, false, 0}
 #define openxc_AcceptanceFilterBypassCommand_init_zero {false, 0, false, 0}
+#define openxc_MessageFormatCommand_init_zero    {false, 0, false, (openxc_MessageFormatCommand_MessageFormat)0}
 #define openxc_CommandResponse_init_zero         {false, (openxc_ControlCommand_Type)0, false, "", false, 0}
 #define openxc_DiagnosticRequest_init_zero       {false, 0, false, 0, false, 0, false, 0, false, {0, {0}}, false, 0, false, 0, false, "", false, (openxc_DiagnosticRequest_DecodedType)0}
 #define openxc_DiagnosticResponse_init_zero      {false, 0, false, 0, false, 0, false, 0, false, 0, false, 0, false, {0, {0}}, false, 0}
@@ -242,6 +259,8 @@ typedef struct _openxc_VehicleMessage {
 #define openxc_DynamicField_string_value_tag     2
 #define openxc_DynamicField_numeric_value_tag    3
 #define openxc_DynamicField_boolean_value_tag    4
+#define openxc_MessageFormatCommand_bus_tag      1
+#define openxc_MessageFormatCommand_format_tag   2
 #define openxc_PassthroughModeControlCommand_bus_tag 1
 #define openxc_PassthroughModeControlCommand_enabled_tag 2
 #define openxc_RawMessage_bus_tag                1
@@ -257,6 +276,7 @@ typedef struct _openxc_VehicleMessage {
 #define openxc_ControlCommand_diagnostic_request_tag 2
 #define openxc_ControlCommand_passthrough_mode_request_tag 3
 #define openxc_ControlCommand_acceptance_filter_bypass_command_tag 4
+#define openxc_ControlCommand_message_format_command_tag 5
 #define openxc_VehicleMessage_type_tag           1
 #define openxc_VehicleMessage_raw_message_tag    2
 #define openxc_VehicleMessage_translated_message_tag 3
@@ -267,10 +287,11 @@ typedef struct _openxc_VehicleMessage {
 /* Struct field encoding specification for nanopb */
 extern const pb_field_t openxc_VehicleMessage_fields[7];
 extern const pb_field_t openxc_RawMessage_fields[4];
-extern const pb_field_t openxc_ControlCommand_fields[5];
+extern const pb_field_t openxc_ControlCommand_fields[6];
 extern const pb_field_t openxc_DiagnosticControlCommand_fields[3];
 extern const pb_field_t openxc_PassthroughModeControlCommand_fields[3];
 extern const pb_field_t openxc_AcceptanceFilterBypassCommand_fields[3];
+extern const pb_field_t openxc_MessageFormatCommand_fields[3];
 extern const pb_field_t openxc_CommandResponse_fields[4];
 extern const pb_field_t openxc_DiagnosticRequest_fields[10];
 extern const pb_field_t openxc_DiagnosticResponse_fields[9];
@@ -278,12 +299,13 @@ extern const pb_field_t openxc_DynamicField_fields[5];
 extern const pb_field_t openxc_TranslatedMessage_fields[5];
 
 /* Maximum encoded size of messages (where known) */
-#define openxc_VehicleMessage_size               704
+#define openxc_VehicleMessage_size               724
 #define openxc_RawMessage_size                   27
-#define openxc_ControlCommand_size               114
+#define openxc_ControlCommand_size               133
 #define openxc_DiagnosticControlCommand_size     76
 #define openxc_PassthroughModeControlCommand_size 13
 #define openxc_AcceptanceFilterBypassCommand_size 13
+#define openxc_MessageFormatCommand_size         17
 #define openxc_CommandResponse_size              139
 #define openxc_DiagnosticRequest_size            68
 #define openxc_DiagnosticResponse_size           56
diff --git a/gen/java/com/openxc/BinaryMessages.java b/gen/java/com/openxc/BinaryMessages.java
index e46cab69..7a745c5c 100644
--- a/gen/java/com/openxc/BinaryMessages.java
+++ b/gen/java/com/openxc/BinaryMessages.java
@@ -2097,6 +2097,20 @@ public final class BinaryMessages {
      * <code>optional .openxc.AcceptanceFilterBypassCommand acceptance_filter_bypass_command = 4;</code>
      */
     com.openxc.BinaryMessages.AcceptanceFilterBypassCommandOrBuilder getAcceptanceFilterBypassCommandOrBuilder();
+
+    // optional .openxc.MessageFormatCommand message_format_command = 5;
+    /**
+     * <code>optional .openxc.MessageFormatCommand message_format_command = 5;</code>
+     */
+    boolean hasMessageFormatCommand();
+    /**
+     * <code>optional .openxc.MessageFormatCommand message_format_command = 5;</code>
+     */
+    com.openxc.BinaryMessages.MessageFormatCommand getMessageFormatCommand();
+    /**
+     * <code>optional .openxc.MessageFormatCommand message_format_command = 5;</code>
+     */
+    com.openxc.BinaryMessages.MessageFormatCommandOrBuilder getMessageFormatCommandOrBuilder();
   }
   /**
    * Protobuf type {@code openxc.ControlCommand}
@@ -2199,6 +2213,19 @@ public final class BinaryMessages {
               bitField0_ |= 0x00000008;
               break;
             }
+            case 42: {
+              com.openxc.BinaryMessages.MessageFormatCommand.Builder subBuilder = null;
+              if (((bitField0_ & 0x00000010) == 0x00000010)) {
+                subBuilder = messageFormatCommand_.toBuilder();
+              }
+              messageFormatCommand_ = input.readMessage(com.openxc.BinaryMessages.MessageFormatCommand.PARSER, extensionRegistry);
+              if (subBuilder != null) {
+                subBuilder.mergeFrom(messageFormatCommand_);
+                messageFormatCommand_ = subBuilder.buildPartial();
+              }
+              bitField0_ |= 0x00000010;
+              break;
+            }
           }
         }
       } catch (com.google.protobuf.InvalidProtocolBufferException e) {
@@ -2263,6 +2290,10 @@ public final class BinaryMessages {
        * <code>ACCEPTANCE_FILTER_BYPASS = 5;</code>
        */
       ACCEPTANCE_FILTER_BYPASS(4, 5),
+      /**
+       * <code>MESSAGE_FORMAT = 6;</code>
+       */
+      MESSAGE_FORMAT(5, 6),
       ;
 
       /**
@@ -2285,6 +2316,10 @@ public final class BinaryMessages {
        * <code>ACCEPTANCE_FILTER_BYPASS = 5;</code>
        */
       public static final int ACCEPTANCE_FILTER_BYPASS_VALUE = 5;
+      /**
+       * <code>MESSAGE_FORMAT = 6;</code>
+       */
+      public static final int MESSAGE_FORMAT_VALUE = 6;
 
 
       public final int getNumber() { return value; }
@@ -2296,6 +2331,7 @@ public final class BinaryMessages {
           case 3: return DIAGNOSTIC;
           case 4: return PASSTHROUGH;
           case 5: return ACCEPTANCE_FILTER_BYPASS;
+          case 6: return MESSAGE_FORMAT;
           default: return null;
         }
       }
@@ -2430,11 +2466,34 @@ public final class BinaryMessages {
       return acceptanceFilterBypassCommand_;
     }
 
+    // optional .openxc.MessageFormatCommand message_format_command = 5;
+    public static final int MESSAGE_FORMAT_COMMAND_FIELD_NUMBER = 5;
+    private com.openxc.BinaryMessages.MessageFormatCommand messageFormatCommand_;
+    /**
+     * <code>optional .openxc.MessageFormatCommand message_format_command = 5;</code>
+     */
+    public boolean hasMessageFormatCommand() {
+      return ((bitField0_ & 0x00000010) == 0x00000010);
+    }
+    /**
+     * <code>optional .openxc.MessageFormatCommand message_format_command = 5;</code>
+     */
+    public com.openxc.BinaryMessages.MessageFormatCommand getMessageFormatCommand() {
+      return messageFormatCommand_;
+    }
+    /**
+     * <code>optional .openxc.MessageFormatCommand message_format_command = 5;</code>
+     */
+    public com.openxc.BinaryMessages.MessageFormatCommandOrBuilder getMessageFormatCommandOrBuilder() {
+      return messageFormatCommand_;
+    }
+
     private void initFields() {
       type_ = com.openxc.BinaryMessages.ControlCommand.Type.VERSION;
       diagnosticRequest_ = com.openxc.BinaryMessages.DiagnosticControlCommand.getDefaultInstance();
       passthroughModeRequest_ = com.openxc.BinaryMessages.PassthroughModeControlCommand.getDefaultInstance();
       acceptanceFilterBypassCommand_ = com.openxc.BinaryMessages.AcceptanceFilterBypassCommand.getDefaultInstance();
+      messageFormatCommand_ = com.openxc.BinaryMessages.MessageFormatCommand.getDefaultInstance();
     }
     private byte memoizedIsInitialized = -1;
     public final boolean isInitialized() {
@@ -2460,6 +2519,9 @@ public final class BinaryMessages {
       if (((bitField0_ & 0x00000008) == 0x00000008)) {
         output.writeMessage(4, acceptanceFilterBypassCommand_);
       }
+      if (((bitField0_ & 0x00000010) == 0x00000010)) {
+        output.writeMessage(5, messageFormatCommand_);
+      }
       getUnknownFields().writeTo(output);
     }
 
@@ -2485,6 +2547,10 @@ public final class BinaryMessages {
         size += com.google.protobuf.CodedOutputStream
           .computeMessageSize(4, acceptanceFilterBypassCommand_);
       }
+      if (((bitField0_ & 0x00000010) == 0x00000010)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeMessageSize(5, messageFormatCommand_);
+      }
       size += getUnknownFields().getSerializedSize();
       memoizedSerializedSize = size;
       return size;
@@ -2596,6 +2662,7 @@ public final class BinaryMessages {
           getDiagnosticRequestFieldBuilder();
           getPassthroughModeRequestFieldBuilder();
           getAcceptanceFilterBypassCommandFieldBuilder();
+          getMessageFormatCommandFieldBuilder();
         }
       }
       private static Builder create() {
@@ -2624,6 +2691,12 @@ public final class BinaryMessages {
           acceptanceFilterBypassCommandBuilder_.clear();
         }
         bitField0_ = (bitField0_ & ~0x00000008);
+        if (messageFormatCommandBuilder_ == null) {
+          messageFormatCommand_ = com.openxc.BinaryMessages.MessageFormatCommand.getDefaultInstance();
+        } else {
+          messageFormatCommandBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000010);
         return this;
       }
 
@@ -2680,6 +2753,14 @@ public final class BinaryMessages {
         } else {
           result.acceptanceFilterBypassCommand_ = acceptanceFilterBypassCommandBuilder_.build();
         }
+        if (((from_bitField0_ & 0x00000010) == 0x00000010)) {
+          to_bitField0_ |= 0x00000010;
+        }
+        if (messageFormatCommandBuilder_ == null) {
+          result.messageFormatCommand_ = messageFormatCommand_;
+        } else {
+          result.messageFormatCommand_ = messageFormatCommandBuilder_.build();
+        }
         result.bitField0_ = to_bitField0_;
         onBuilt();
         return result;
@@ -2708,6 +2789,9 @@ public final class BinaryMessages {
         if (other.hasAcceptanceFilterBypassCommand()) {
           mergeAcceptanceFilterBypassCommand(other.getAcceptanceFilterBypassCommand());
         }
+        if (other.hasMessageFormatCommand()) {
+          mergeMessageFormatCommand(other.getMessageFormatCommand());
+        }
         this.mergeUnknownFields(other.getUnknownFields());
         return this;
       }
@@ -3122,6 +3206,123 @@ public final class BinaryMessages {
         return acceptanceFilterBypassCommandBuilder_;
       }
 
+      // optional .openxc.MessageFormatCommand message_format_command = 5;
+      private com.openxc.BinaryMessages.MessageFormatCommand messageFormatCommand_ = com.openxc.BinaryMessages.MessageFormatCommand.getDefaultInstance();
+      private com.google.protobuf.SingleFieldBuilder<
+          com.openxc.BinaryMessages.MessageFormatCommand, com.openxc.BinaryMessages.MessageFormatCommand.Builder, com.openxc.BinaryMessages.MessageFormatCommandOrBuilder> messageFormatCommandBuilder_;
+      /**
+       * <code>optional .openxc.MessageFormatCommand message_format_command = 5;</code>
+       */
+      public boolean hasMessageFormatCommand() {
+        return ((bitField0_ & 0x00000010) == 0x00000010);
+      }
+      /**
+       * <code>optional .openxc.MessageFormatCommand message_format_command = 5;</code>
+       */
+      public com.openxc.BinaryMessages.MessageFormatCommand getMessageFormatCommand() {
+        if (messageFormatCommandBuilder_ == null) {
+          return messageFormatCommand_;
+        } else {
+          return messageFormatCommandBuilder_.getMessage();
+        }
+      }
+      /**
+       * <code>optional .openxc.MessageFormatCommand message_format_command = 5;</code>
+       */
+      public Builder setMessageFormatCommand(com.openxc.BinaryMessages.MessageFormatCommand value) {
+        if (messageFormatCommandBuilder_ == null) {
+          if (value == null) {
+            throw new NullPointerException();
+          }
+          messageFormatCommand_ = value;
+          onChanged();
+        } else {
+          messageFormatCommandBuilder_.setMessage(value);
+        }
+        bitField0_ |= 0x00000010;
+        return this;
+      }
+      /**
+       * <code>optional .openxc.MessageFormatCommand message_format_command = 5;</code>
+       */
+      public Builder setMessageFormatCommand(
+          com.openxc.BinaryMessages.MessageFormatCommand.Builder builderForValue) {
+        if (messageFormatCommandBuilder_ == null) {
+          messageFormatCommand_ = builderForValue.build();
+          onChanged();
+        } else {
+          messageFormatCommandBuilder_.setMessage(builderForValue.build());
+        }
+        bitField0_ |= 0x00000010;
+        return this;
+      }
+      /**
+       * <code>optional .openxc.MessageFormatCommand message_format_command = 5;</code>
+       */
+      public Builder mergeMessageFormatCommand(com.openxc.BinaryMessages.MessageFormatCommand value) {
+        if (messageFormatCommandBuilder_ == null) {
+          if (((bitField0_ & 0x00000010) == 0x00000010) &&
+              messageFormatCommand_ != com.openxc.BinaryMessages.MessageFormatCommand.getDefaultInstance()) {
+            messageFormatCommand_ =
+              com.openxc.BinaryMessages.MessageFormatCommand.newBuilder(messageFormatCommand_).mergeFrom(value).buildPartial();
+          } else {
+            messageFormatCommand_ = value;
+          }
+          onChanged();
+        } else {
+          messageFormatCommandBuilder_.mergeFrom(value);
+        }
+        bitField0_ |= 0x00000010;
+        return this;
+      }
+      /**
+       * <code>optional .openxc.MessageFormatCommand message_format_command = 5;</code>
+       */
+      public Builder clearMessageFormatCommand() {
+        if (messageFormatCommandBuilder_ == null) {
+          messageFormatCommand_ = com.openxc.BinaryMessages.MessageFormatCommand.getDefaultInstance();
+          onChanged();
+        } else {
+          messageFormatCommandBuilder_.clear();
+        }
+        bitField0_ = (bitField0_ & ~0x00000010);
+        return this;
+      }
+      /**
+       * <code>optional .openxc.MessageFormatCommand message_format_command = 5;</code>
+       */
+      public com.openxc.BinaryMessages.MessageFormatCommand.Builder getMessageFormatCommandBuilder() {
+        bitField0_ |= 0x00000010;
+        onChanged();
+        return getMessageFormatCommandFieldBuilder().getBuilder();
+      }
+      /**
+       * <code>optional .openxc.MessageFormatCommand message_format_command = 5;</code>
+       */
+      public com.openxc.BinaryMessages.MessageFormatCommandOrBuilder getMessageFormatCommandOrBuilder() {
+        if (messageFormatCommandBuilder_ != null) {
+          return messageFormatCommandBuilder_.getMessageOrBuilder();
+        } else {
+          return messageFormatCommand_;
+        }
+      }
+      /**
+       * <code>optional .openxc.MessageFormatCommand message_format_command = 5;</code>
+       */
+      private com.google.protobuf.SingleFieldBuilder<
+          com.openxc.BinaryMessages.MessageFormatCommand, com.openxc.BinaryMessages.MessageFormatCommand.Builder, com.openxc.BinaryMessages.MessageFormatCommandOrBuilder> 
+          getMessageFormatCommandFieldBuilder() {
+        if (messageFormatCommandBuilder_ == null) {
+          messageFormatCommandBuilder_ = new com.google.protobuf.SingleFieldBuilder<
+              com.openxc.BinaryMessages.MessageFormatCommand, com.openxc.BinaryMessages.MessageFormatCommand.Builder, com.openxc.BinaryMessages.MessageFormatCommandOrBuilder>(
+                  messageFormatCommand_,
+                  getParentForChildren(),
+                  isClean());
+          messageFormatCommand_ = null;
+        }
+        return messageFormatCommandBuilder_;
+      }
+
       // @@protoc_insertion_point(builder_scope:openxc.ControlCommand)
     }
 
@@ -4766,6 +4967,574 @@ public final class BinaryMessages {
     // @@protoc_insertion_point(class_scope:openxc.AcceptanceFilterBypassCommand)
   }
 
+  public interface MessageFormatCommandOrBuilder
+      extends com.google.protobuf.MessageOrBuilder {
+
+    // optional int32 bus = 1;
+    /**
+     * <code>optional int32 bus = 1;</code>
+     */
+    boolean hasBus();
+    /**
+     * <code>optional int32 bus = 1;</code>
+     */
+    int getBus();
+
+    // optional .openxc.MessageFormatCommand.MessageFormat format = 2;
+    /**
+     * <code>optional .openxc.MessageFormatCommand.MessageFormat format = 2;</code>
+     */
+    boolean hasFormat();
+    /**
+     * <code>optional .openxc.MessageFormatCommand.MessageFormat format = 2;</code>
+     */
+    com.openxc.BinaryMessages.MessageFormatCommand.MessageFormat getFormat();
+  }
+  /**
+   * Protobuf type {@code openxc.MessageFormatCommand}
+   */
+  public static final class MessageFormatCommand extends
+      com.google.protobuf.GeneratedMessage
+      implements MessageFormatCommandOrBuilder {
+    // Use MessageFormatCommand.newBuilder() to construct.
+    private MessageFormatCommand(com.google.protobuf.GeneratedMessage.Builder<?> builder) {
+      super(builder);
+      this.unknownFields = builder.getUnknownFields();
+    }
+    private MessageFormatCommand(boolean noInit) { this.unknownFields = com.google.protobuf.UnknownFieldSet.getDefaultInstance(); }
+
+    private static final MessageFormatCommand defaultInstance;
+    public static MessageFormatCommand getDefaultInstance() {
+      return defaultInstance;
+    }
+
+    public MessageFormatCommand getDefaultInstanceForType() {
+      return defaultInstance;
+    }
+
+    private final com.google.protobuf.UnknownFieldSet unknownFields;
+    @java.lang.Override
+    public final com.google.protobuf.UnknownFieldSet
+        getUnknownFields() {
+      return this.unknownFields;
+    }
+    private MessageFormatCommand(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      initFields();
+      int mutable_bitField0_ = 0;
+      com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+          com.google.protobuf.UnknownFieldSet.newBuilder();
+      try {
+        boolean done = false;
+        while (!done) {
+          int tag = input.readTag();
+          switch (tag) {
+            case 0:
+              done = true;
+              break;
+            default: {
+              if (!parseUnknownField(input, unknownFields,
+                                     extensionRegistry, tag)) {
+                done = true;
+              }
+              break;
+            }
+            case 8: {
+              bitField0_ |= 0x00000001;
+              bus_ = input.readInt32();
+              break;
+            }
+            case 16: {
+              int rawValue = input.readEnum();
+              com.openxc.BinaryMessages.MessageFormatCommand.MessageFormat value = com.openxc.BinaryMessages.MessageFormatCommand.MessageFormat.valueOf(rawValue);
+              if (value == null) {
+                unknownFields.mergeVarintField(2, rawValue);
+              } else {
+                bitField0_ |= 0x00000002;
+                format_ = value;
+              }
+              break;
+            }
+          }
+        }
+      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+        throw e.setUnfinishedMessage(this);
+      } catch (java.io.IOException e) {
+        throw new com.google.protobuf.InvalidProtocolBufferException(
+            e.getMessage()).setUnfinishedMessage(this);
+      } finally {
+        this.unknownFields = unknownFields.build();
+        makeExtensionsImmutable();
+      }
+    }
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return com.openxc.BinaryMessages.internal_static_openxc_MessageFormatCommand_descriptor;
+    }
+
+    protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return com.openxc.BinaryMessages.internal_static_openxc_MessageFormatCommand_fieldAccessorTable
+          .ensureFieldAccessorsInitialized(
+              com.openxc.BinaryMessages.MessageFormatCommand.class, com.openxc.BinaryMessages.MessageFormatCommand.Builder.class);
+    }
+
+    public static com.google.protobuf.Parser<MessageFormatCommand> PARSER =
+        new com.google.protobuf.AbstractParser<MessageFormatCommand>() {
+      public MessageFormatCommand parsePartialFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws com.google.protobuf.InvalidProtocolBufferException {
+        return new MessageFormatCommand(input, extensionRegistry);
+      }
+    };
+
+    @java.lang.Override
+    public com.google.protobuf.Parser<MessageFormatCommand> getParserForType() {
+      return PARSER;
+    }
+
+    /**
+     * Protobuf enum {@code openxc.MessageFormatCommand.MessageFormat}
+     */
+    public enum MessageFormat
+        implements com.google.protobuf.ProtocolMessageEnum {
+      /**
+       * <code>JSON = 1;</code>
+       */
+      JSON(0, 1),
+      /**
+       * <code>BINARY = 2;</code>
+       */
+      BINARY(1, 2),
+      ;
+
+      /**
+       * <code>JSON = 1;</code>
+       */
+      public static final int JSON_VALUE = 1;
+      /**
+       * <code>BINARY = 2;</code>
+       */
+      public static final int BINARY_VALUE = 2;
+
+
+      public final int getNumber() { return value; }
+
+      public static MessageFormat valueOf(int value) {
+        switch (value) {
+          case 1: return JSON;
+          case 2: return BINARY;
+          default: return null;
+        }
+      }
+
+      public static com.google.protobuf.Internal.EnumLiteMap<MessageFormat>
+          internalGetValueMap() {
+        return internalValueMap;
+      }
+      private static com.google.protobuf.Internal.EnumLiteMap<MessageFormat>
+          internalValueMap =
+            new com.google.protobuf.Internal.EnumLiteMap<MessageFormat>() {
+              public MessageFormat findValueByNumber(int number) {
+                return MessageFormat.valueOf(number);
+              }
+            };
+
+      public final com.google.protobuf.Descriptors.EnumValueDescriptor
+          getValueDescriptor() {
+        return getDescriptor().getValues().get(index);
+      }
+      public final com.google.protobuf.Descriptors.EnumDescriptor
+          getDescriptorForType() {
+        return getDescriptor();
+      }
+      public static final com.google.protobuf.Descriptors.EnumDescriptor
+          getDescriptor() {
+        return com.openxc.BinaryMessages.MessageFormatCommand.getDescriptor().getEnumTypes().get(0);
+      }
+
+      private static final MessageFormat[] VALUES = values();
+
+      public static MessageFormat valueOf(
+          com.google.protobuf.Descriptors.EnumValueDescriptor desc) {
+        if (desc.getType() != getDescriptor()) {
+          throw new java.lang.IllegalArgumentException(
+            "EnumValueDescriptor is not for this type.");
+        }
+        return VALUES[desc.getIndex()];
+      }
+
+      private final int index;
+      private final int value;
+
+      private MessageFormat(int index, int value) {
+        this.index = index;
+        this.value = value;
+      }
+
+      // @@protoc_insertion_point(enum_scope:openxc.MessageFormatCommand.MessageFormat)
+    }
+
+    private int bitField0_;
+    // optional int32 bus = 1;
+    public static final int BUS_FIELD_NUMBER = 1;
+    private int bus_;
+    /**
+     * <code>optional int32 bus = 1;</code>
+     */
+    public boolean hasBus() {
+      return ((bitField0_ & 0x00000001) == 0x00000001);
+    }
+    /**
+     * <code>optional int32 bus = 1;</code>
+     */
+    public int getBus() {
+      return bus_;
+    }
+
+    // optional .openxc.MessageFormatCommand.MessageFormat format = 2;
+    public static final int FORMAT_FIELD_NUMBER = 2;
+    private com.openxc.BinaryMessages.MessageFormatCommand.MessageFormat format_;
+    /**
+     * <code>optional .openxc.MessageFormatCommand.MessageFormat format = 2;</code>
+     */
+    public boolean hasFormat() {
+      return ((bitField0_ & 0x00000002) == 0x00000002);
+    }
+    /**
+     * <code>optional .openxc.MessageFormatCommand.MessageFormat format = 2;</code>
+     */
+    public com.openxc.BinaryMessages.MessageFormatCommand.MessageFormat getFormat() {
+      return format_;
+    }
+
+    private void initFields() {
+      bus_ = 0;
+      format_ = com.openxc.BinaryMessages.MessageFormatCommand.MessageFormat.JSON;
+    }
+    private byte memoizedIsInitialized = -1;
+    public final boolean isInitialized() {
+      byte isInitialized = memoizedIsInitialized;
+      if (isInitialized != -1) return isInitialized == 1;
+
+      memoizedIsInitialized = 1;
+      return true;
+    }
+
+    public void writeTo(com.google.protobuf.CodedOutputStream output)
+                        throws java.io.IOException {
+      getSerializedSize();
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        output.writeInt32(1, bus_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        output.writeEnum(2, format_.getNumber());
+      }
+      getUnknownFields().writeTo(output);
+    }
+
+    private int memoizedSerializedSize = -1;
+    public int getSerializedSize() {
+      int size = memoizedSerializedSize;
+      if (size != -1) return size;
+
+      size = 0;
+      if (((bitField0_ & 0x00000001) == 0x00000001)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeInt32Size(1, bus_);
+      }
+      if (((bitField0_ & 0x00000002) == 0x00000002)) {
+        size += com.google.protobuf.CodedOutputStream
+          .computeEnumSize(2, format_.getNumber());
+      }
+      size += getUnknownFields().getSerializedSize();
+      memoizedSerializedSize = size;
+      return size;
+    }
+
+    private static final long serialVersionUID = 0L;
+    @java.lang.Override
+    protected java.lang.Object writeReplace()
+        throws java.io.ObjectStreamException {
+      return super.writeReplace();
+    }
+
+    public static com.openxc.BinaryMessages.MessageFormatCommand parseFrom(
+        com.google.protobuf.ByteString data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static com.openxc.BinaryMessages.MessageFormatCommand parseFrom(
+        com.google.protobuf.ByteString data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static com.openxc.BinaryMessages.MessageFormatCommand parseFrom(byte[] data)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data);
+    }
+    public static com.openxc.BinaryMessages.MessageFormatCommand parseFrom(
+        byte[] data,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return PARSER.parseFrom(data, extensionRegistry);
+    }
+    public static com.openxc.BinaryMessages.MessageFormatCommand parseFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static com.openxc.BinaryMessages.MessageFormatCommand parseFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+    public static com.openxc.BinaryMessages.MessageFormatCommand parseDelimitedFrom(java.io.InputStream input)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input);
+    }
+    public static com.openxc.BinaryMessages.MessageFormatCommand parseDelimitedFrom(
+        java.io.InputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseDelimitedFrom(input, extensionRegistry);
+    }
+    public static com.openxc.BinaryMessages.MessageFormatCommand parseFrom(
+        com.google.protobuf.CodedInputStream input)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input);
+    }
+    public static com.openxc.BinaryMessages.MessageFormatCommand parseFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      return PARSER.parseFrom(input, extensionRegistry);
+    }
+
+    public static Builder newBuilder() { return Builder.create(); }
+    public Builder newBuilderForType() { return newBuilder(); }
+    public static Builder newBuilder(com.openxc.BinaryMessages.MessageFormatCommand prototype) {
+      return newBuilder().mergeFrom(prototype);
+    }
+    public Builder toBuilder() { return newBuilder(this); }
+
+    @java.lang.Override
+    protected Builder newBuilderForType(
+        com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+      Builder builder = new Builder(parent);
+      return builder;
+    }
+    /**
+     * Protobuf type {@code openxc.MessageFormatCommand}
+     */
+    public static final class Builder extends
+        com.google.protobuf.GeneratedMessage.Builder<Builder>
+       implements com.openxc.BinaryMessages.MessageFormatCommandOrBuilder {
+      public static final com.google.protobuf.Descriptors.Descriptor
+          getDescriptor() {
+        return com.openxc.BinaryMessages.internal_static_openxc_MessageFormatCommand_descriptor;
+      }
+
+      protected com.google.protobuf.GeneratedMessage.FieldAccessorTable
+          internalGetFieldAccessorTable() {
+        return com.openxc.BinaryMessages.internal_static_openxc_MessageFormatCommand_fieldAccessorTable
+            .ensureFieldAccessorsInitialized(
+                com.openxc.BinaryMessages.MessageFormatCommand.class, com.openxc.BinaryMessages.MessageFormatCommand.Builder.class);
+      }
+
+      // Construct using com.openxc.BinaryMessages.MessageFormatCommand.newBuilder()
+      private Builder() {
+        maybeForceBuilderInitialization();
+      }
+
+      private Builder(
+          com.google.protobuf.GeneratedMessage.BuilderParent parent) {
+        super(parent);
+        maybeForceBuilderInitialization();
+      }
+      private void maybeForceBuilderInitialization() {
+        if (com.google.protobuf.GeneratedMessage.alwaysUseFieldBuilders) {
+        }
+      }
+      private static Builder create() {
+        return new Builder();
+      }
+
+      public Builder clear() {
+        super.clear();
+        bus_ = 0;
+        bitField0_ = (bitField0_ & ~0x00000001);
+        format_ = com.openxc.BinaryMessages.MessageFormatCommand.MessageFormat.JSON;
+        bitField0_ = (bitField0_ & ~0x00000002);
+        return this;
+      }
+
+      public Builder clone() {
+        return create().mergeFrom(buildPartial());
+      }
+
+      public com.google.protobuf.Descriptors.Descriptor
+          getDescriptorForType() {
+        return com.openxc.BinaryMessages.internal_static_openxc_MessageFormatCommand_descriptor;
+      }
+
+      public com.openxc.BinaryMessages.MessageFormatCommand getDefaultInstanceForType() {
+        return com.openxc.BinaryMessages.MessageFormatCommand.getDefaultInstance();
+      }
+
+      public com.openxc.BinaryMessages.MessageFormatCommand build() {
+        com.openxc.BinaryMessages.MessageFormatCommand result = buildPartial();
+        if (!result.isInitialized()) {
+          throw newUninitializedMessageException(result);
+        }
+        return result;
+      }
+
+      public com.openxc.BinaryMessages.MessageFormatCommand buildPartial() {
+        com.openxc.BinaryMessages.MessageFormatCommand result = new com.openxc.BinaryMessages.MessageFormatCommand(this);
+        int from_bitField0_ = bitField0_;
+        int to_bitField0_ = 0;
+        if (((from_bitField0_ & 0x00000001) == 0x00000001)) {
+          to_bitField0_ |= 0x00000001;
+        }
+        result.bus_ = bus_;
+        if (((from_bitField0_ & 0x00000002) == 0x00000002)) {
+          to_bitField0_ |= 0x00000002;
+        }
+        result.format_ = format_;
+        result.bitField0_ = to_bitField0_;
+        onBuilt();
+        return result;
+      }
+
+      public Builder mergeFrom(com.google.protobuf.Message other) {
+        if (other instanceof com.openxc.BinaryMessages.MessageFormatCommand) {
+          return mergeFrom((com.openxc.BinaryMessages.MessageFormatCommand)other);
+        } else {
+          super.mergeFrom(other);
+          return this;
+        }
+      }
+
+      public Builder mergeFrom(com.openxc.BinaryMessages.MessageFormatCommand other) {
+        if (other == com.openxc.BinaryMessages.MessageFormatCommand.getDefaultInstance()) return this;
+        if (other.hasBus()) {
+          setBus(other.getBus());
+        }
+        if (other.hasFormat()) {
+          setFormat(other.getFormat());
+        }
+        this.mergeUnknownFields(other.getUnknownFields());
+        return this;
+      }
+
+      public final boolean isInitialized() {
+        return true;
+      }
+
+      public Builder mergeFrom(
+          com.google.protobuf.CodedInputStream input,
+          com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+          throws java.io.IOException {
+        com.openxc.BinaryMessages.MessageFormatCommand parsedMessage = null;
+        try {
+          parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+        } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+          parsedMessage = (com.openxc.BinaryMessages.MessageFormatCommand) e.getUnfinishedMessage();
+          throw e;
+        } finally {
+          if (parsedMessage != null) {
+            mergeFrom(parsedMessage);
+          }
+        }
+        return this;
+      }
+      private int bitField0_;
+
+      // optional int32 bus = 1;
+      private int bus_ ;
+      /**
+       * <code>optional int32 bus = 1;</code>
+       */
+      public boolean hasBus() {
+        return ((bitField0_ & 0x00000001) == 0x00000001);
+      }
+      /**
+       * <code>optional int32 bus = 1;</code>
+       */
+      public int getBus() {
+        return bus_;
+      }
+      /**
+       * <code>optional int32 bus = 1;</code>
+       */
+      public Builder setBus(int value) {
+        bitField0_ |= 0x00000001;
+        bus_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional int32 bus = 1;</code>
+       */
+      public Builder clearBus() {
+        bitField0_ = (bitField0_ & ~0x00000001);
+        bus_ = 0;
+        onChanged();
+        return this;
+      }
+
+      // optional .openxc.MessageFormatCommand.MessageFormat format = 2;
+      private com.openxc.BinaryMessages.MessageFormatCommand.MessageFormat format_ = com.openxc.BinaryMessages.MessageFormatCommand.MessageFormat.JSON;
+      /**
+       * <code>optional .openxc.MessageFormatCommand.MessageFormat format = 2;</code>
+       */
+      public boolean hasFormat() {
+        return ((bitField0_ & 0x00000002) == 0x00000002);
+      }
+      /**
+       * <code>optional .openxc.MessageFormatCommand.MessageFormat format = 2;</code>
+       */
+      public com.openxc.BinaryMessages.MessageFormatCommand.MessageFormat getFormat() {
+        return format_;
+      }
+      /**
+       * <code>optional .openxc.MessageFormatCommand.MessageFormat format = 2;</code>
+       */
+      public Builder setFormat(com.openxc.BinaryMessages.MessageFormatCommand.MessageFormat value) {
+        if (value == null) {
+          throw new NullPointerException();
+        }
+        bitField0_ |= 0x00000002;
+        format_ = value;
+        onChanged();
+        return this;
+      }
+      /**
+       * <code>optional .openxc.MessageFormatCommand.MessageFormat format = 2;</code>
+       */
+      public Builder clearFormat() {
+        bitField0_ = (bitField0_ & ~0x00000002);
+        format_ = com.openxc.BinaryMessages.MessageFormatCommand.MessageFormat.JSON;
+        onChanged();
+        return this;
+      }
+
+      // @@protoc_insertion_point(builder_scope:openxc.MessageFormatCommand)
+    }
+
+    static {
+      defaultInstance = new MessageFormatCommand(true);
+      defaultInstance.initFields();
+    }
+
+    // @@protoc_insertion_point(class_scope:openxc.MessageFormatCommand)
+  }
+
   public interface CommandResponseOrBuilder
       extends com.google.protobuf.MessageOrBuilder {
 
@@ -9575,6 +10344,11 @@ public final class BinaryMessages {
     com.google.protobuf.GeneratedMessage.FieldAccessorTable
       internal_static_openxc_AcceptanceFilterBypassCommand_fieldAccessorTable;
   private static com.google.protobuf.Descriptors.Descriptor
+    internal_static_openxc_MessageFormatCommand_descriptor;
+  private static
+    com.google.protobuf.GeneratedMessage.FieldAccessorTable
+      internal_static_openxc_MessageFormatCommand_fieldAccessorTable;
+  private static com.google.protobuf.Descriptors.Descriptor
     internal_static_openxc_CommandResponse_descriptor;
   private static
     com.google.protobuf.GeneratedMessage.FieldAccessorTable
@@ -9620,47 +10394,53 @@ public final class BinaryMessages {
       "ANSLATED\020\002\022\016\n\nDIAGNOSTIC\020\003\022\023\n\017CONTROL_CO",
       "MMAND\020\004\022\024\n\020COMMAND_RESPONSE\020\005\";\n\nRawMess" +
       "age\022\013\n\003bus\030\001 \001(\005\022\022\n\nmessage_id\030\002 \001(\r\022\014\n\004" +
-      "data\030\003 \001(\014\"\366\002\n\016ControlCommand\022)\n\004type\030\001 " +
+      "data\030\003 \001(\014\"\310\003\n\016ControlCommand\022)\n\004type\030\001 " +
       "\001(\0162\033.openxc.ControlCommand.Type\022<\n\022diag" +
       "nostic_request\030\002 \001(\0132 .openxc.Diagnostic" +
       "ControlCommand\022G\n\030passthrough_mode_reque" +
       "st\030\003 \001(\0132%.openxc.PassthroughModeControl" +
       "Command\022O\n acceptance_filter_bypass_comm" +
       "and\030\004 \001(\0132%.openxc.AcceptanceFilterBypas" +
-      "sCommand\"a\n\004Type\022\013\n\007VERSION\020\001\022\r\n\tDEVICE_",
-      "ID\020\002\022\016\n\nDIAGNOSTIC\020\003\022\017\n\013PASSTHROUGH\020\004\022\034\n" +
-      "\030ACCEPTANCE_FILTER_BYPASS\020\005\"\236\001\n\030Diagnost" +
-      "icControlCommand\022*\n\007request\030\001 \001(\0132\031.open" +
-      "xc.DiagnosticRequest\0227\n\006action\030\002 \001(\0162\'.o" +
-      "penxc.DiagnosticControlCommand.Action\"\035\n" +
-      "\006Action\022\007\n\003ADD\020\001\022\n\n\006CANCEL\020\002\"=\n\035Passthro" +
-      "ughModeControlCommand\022\013\n\003bus\030\001 \001(\005\022\017\n\007en" +
-      "abled\030\002 \001(\010\"<\n\035AcceptanceFilterBypassCom" +
-      "mand\022\013\n\003bus\030\001 \001(\005\022\016\n\006bypass\030\002 \001(\010\"]\n\017Com" +
-      "mandResponse\022)\n\004type\030\001 \001(\0162\033.openxc.Cont",
-      "rolCommand.Type\022\017\n\007message\030\002 \001(\t\022\016\n\006stat" +
-      "us\030\003 \001(\010\"\375\001\n\021DiagnosticRequest\022\013\n\003bus\030\001 " +
-      "\001(\005\022\022\n\nmessage_id\030\002 \001(\r\022\014\n\004mode\030\003 \001(\r\022\013\n" +
-      "\003pid\030\004 \001(\r\022\017\n\007payload\030\005 \001(\014\022\032\n\022multiple_" +
-      "responses\030\006 \001(\010\022\021\n\tfrequency\030\007 \001(\001\022\014\n\004na" +
-      "me\030\010 \001(\t\022;\n\014decoded_type\030\t \001(\0162%.openxc." +
-      "DiagnosticRequest.DecodedType\"!\n\013Decoded" +
-      "Type\022\010\n\004NONE\020\001\022\010\n\004OBD2\020\002\"\241\001\n\022DiagnosticR" +
-      "esponse\022\013\n\003bus\030\001 \001(\005\022\022\n\nmessage_id\030\002 \001(\r" +
-      "\022\014\n\004mode\030\003 \001(\r\022\013\n\003pid\030\004 \001(\r\022\017\n\007success\030\005",
-      " \001(\010\022\036\n\026negative_response_code\030\006 \001(\r\022\017\n\007" +
-      "payload\030\007 \001(\014\022\r\n\005value\030\010 \001(\001\"\242\001\n\014Dynamic" +
-      "Field\022\'\n\004type\030\001 \001(\0162\031.openxc.DynamicFiel" +
-      "d.Type\022\024\n\014string_value\030\002 \001(\t\022\025\n\rnumeric_" +
-      "value\030\003 \001(\001\022\025\n\rboolean_value\030\004 \001(\010\"%\n\004Ty" +
-      "pe\022\n\n\006STRING\020\001\022\007\n\003NUM\020\002\022\010\n\004BOOL\020\003\"\367\001\n\021Tr" +
-      "anslatedMessage\022,\n\004type\030\001 \001(\0162\036.openxc.T" +
-      "ranslatedMessage.Type\022\014\n\004name\030\002 \001(\t\022#\n\005v" +
-      "alue\030\003 \001(\0132\024.openxc.DynamicField\022#\n\005even" +
-      "t\030\004 \001(\0132\024.openxc.DynamicField\"\\\n\004Type\022\n\n",
-      "\006STRING\020\001\022\007\n\003NUM\020\002\022\010\n\004BOOL\020\003\022\022\n\016EVENTED_" +
-      "STRING\020\004\022\017\n\013EVENTED_NUM\020\005\022\020\n\014EVENTED_BOO" +
-      "L\020\006B\034\n\ncom.openxcB\016BinaryMessages"
+      "sCommand\022<\n\026message_format_command\030\005 \001(\013",
+      "2\034.openxc.MessageFormatCommand\"u\n\004Type\022\013" +
+      "\n\007VERSION\020\001\022\r\n\tDEVICE_ID\020\002\022\016\n\nDIAGNOSTIC" +
+      "\020\003\022\017\n\013PASSTHROUGH\020\004\022\034\n\030ACCEPTANCE_FILTER" +
+      "_BYPASS\020\005\022\022\n\016MESSAGE_FORMAT\020\006\"\236\001\n\030Diagno" +
+      "sticControlCommand\022*\n\007request\030\001 \001(\0132\031.op" +
+      "enxc.DiagnosticRequest\0227\n\006action\030\002 \001(\0162\'" +
+      ".openxc.DiagnosticControlCommand.Action\"" +
+      "\035\n\006Action\022\007\n\003ADD\020\001\022\n\n\006CANCEL\020\002\"=\n\035Passth" +
+      "roughModeControlCommand\022\013\n\003bus\030\001 \001(\005\022\017\n\007" +
+      "enabled\030\002 \001(\010\"<\n\035AcceptanceFilterBypassC",
+      "ommand\022\013\n\003bus\030\001 \001(\005\022\016\n\006bypass\030\002 \001(\010\"\206\001\n\024" +
+      "MessageFormatCommand\022\013\n\003bus\030\001 \001(\005\022:\n\006for" +
+      "mat\030\002 \001(\0162*.openxc.MessageFormatCommand." +
+      "MessageFormat\"%\n\rMessageFormat\022\010\n\004JSON\020\001" +
+      "\022\n\n\006BINARY\020\002\"]\n\017CommandResponse\022)\n\004type\030" +
+      "\001 \001(\0162\033.openxc.ControlCommand.Type\022\017\n\007me" +
+      "ssage\030\002 \001(\t\022\016\n\006status\030\003 \001(\010\"\375\001\n\021Diagnost" +
+      "icRequest\022\013\n\003bus\030\001 \001(\005\022\022\n\nmessage_id\030\002 \001" +
+      "(\r\022\014\n\004mode\030\003 \001(\r\022\013\n\003pid\030\004 \001(\r\022\017\n\007payload" +
+      "\030\005 \001(\014\022\032\n\022multiple_responses\030\006 \001(\010\022\021\n\tfr",
+      "equency\030\007 \001(\001\022\014\n\004name\030\010 \001(\t\022;\n\014decoded_t" +
+      "ype\030\t \001(\0162%.openxc.DiagnosticRequest.Dec" +
+      "odedType\"!\n\013DecodedType\022\010\n\004NONE\020\001\022\010\n\004OBD" +
+      "2\020\002\"\241\001\n\022DiagnosticResponse\022\013\n\003bus\030\001 \001(\005\022" +
+      "\022\n\nmessage_id\030\002 \001(\r\022\014\n\004mode\030\003 \001(\r\022\013\n\003pid" +
+      "\030\004 \001(\r\022\017\n\007success\030\005 \001(\010\022\036\n\026negative_resp" +
+      "onse_code\030\006 \001(\r\022\017\n\007payload\030\007 \001(\014\022\r\n\005valu" +
+      "e\030\010 \001(\001\"\242\001\n\014DynamicField\022\'\n\004type\030\001 \001(\0162\031" +
+      ".openxc.DynamicField.Type\022\024\n\014string_valu" +
+      "e\030\002 \001(\t\022\025\n\rnumeric_value\030\003 \001(\001\022\025\n\rboolea",
+      "n_value\030\004 \001(\010\"%\n\004Type\022\n\n\006STRING\020\001\022\007\n\003NUM" +
+      "\020\002\022\010\n\004BOOL\020\003\"\367\001\n\021TranslatedMessage\022,\n\004ty" +
+      "pe\030\001 \001(\0162\036.openxc.TranslatedMessage.Type" +
+      "\022\014\n\004name\030\002 \001(\t\022#\n\005value\030\003 \001(\0132\024.openxc.D" +
+      "ynamicField\022#\n\005event\030\004 \001(\0132\024.openxc.Dyna" +
+      "micField\"\\\n\004Type\022\n\n\006STRING\020\001\022\007\n\003NUM\020\002\022\010\n" +
+      "\004BOOL\020\003\022\022\n\016EVENTED_STRING\020\004\022\017\n\013EVENTED_N" +
+      "UM\020\005\022\020\n\014EVENTED_BOOL\020\006B\034\n\ncom.openxcB\016Bi" +
+      "naryMessages"
     };
     com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner assigner =
       new com.google.protobuf.Descriptors.FileDescriptor.InternalDescriptorAssigner() {
@@ -9684,7 +10464,7 @@ public final class BinaryMessages {
           internal_static_openxc_ControlCommand_fieldAccessorTable = new
             com.google.protobuf.GeneratedMessage.FieldAccessorTable(
               internal_static_openxc_ControlCommand_descriptor,
-              new java.lang.String[] { "Type", "DiagnosticRequest", "PassthroughModeRequest", "AcceptanceFilterBypassCommand", });
+              new java.lang.String[] { "Type", "DiagnosticRequest", "PassthroughModeRequest", "AcceptanceFilterBypassCommand", "MessageFormatCommand", });
           internal_static_openxc_DiagnosticControlCommand_descriptor =
             getDescriptor().getMessageTypes().get(3);
           internal_static_openxc_DiagnosticControlCommand_fieldAccessorTable = new
@@ -9703,32 +10483,38 @@ public final class BinaryMessages {
             com.google.protobuf.GeneratedMessage.FieldAccessorTable(
               internal_static_openxc_AcceptanceFilterBypassCommand_descriptor,
               new java.lang.String[] { "Bus", "Bypass", });
-          internal_static_openxc_CommandResponse_descriptor =
+          internal_static_openxc_MessageFormatCommand_descriptor =
             getDescriptor().getMessageTypes().get(6);
+          internal_static_openxc_MessageFormatCommand_fieldAccessorTable = new
+            com.google.protobuf.GeneratedMessage.FieldAccessorTable(
+              internal_static_openxc_MessageFormatCommand_descriptor,
+              new java.lang.String[] { "Bus", "Format", });
+          internal_static_openxc_CommandResponse_descriptor =
+            getDescriptor().getMessageTypes().get(7);
           internal_static_openxc_CommandResponse_fieldAccessorTable = new
             com.google.protobuf.GeneratedMessage.FieldAccessorTable(
               internal_static_openxc_CommandResponse_descriptor,
               new java.lang.String[] { "Type", "Message", "Status", });
           internal_static_openxc_DiagnosticRequest_descriptor =
-            getDescriptor().getMessageTypes().get(7);
+            getDescriptor().getMessageTypes().get(8);
           internal_static_openxc_DiagnosticRequest_fieldAccessorTable = new
             com.google.protobuf.GeneratedMessage.FieldAccessorTable(
               internal_static_openxc_DiagnosticRequest_descriptor,
               new java.lang.String[] { "Bus", "MessageId", "Mode", "Pid", "Payload", "MultipleResponses", "Frequency", "Name", "DecodedType", });
           internal_static_openxc_DiagnosticResponse_descriptor =
-            getDescriptor().getMessageTypes().get(8);
+            getDescriptor().getMessageTypes().get(9);
           internal_static_openxc_DiagnosticResponse_fieldAccessorTable = new
             com.google.protobuf.GeneratedMessage.FieldAccessorTable(
               internal_static_openxc_DiagnosticResponse_descriptor,
               new java.lang.String[] { "Bus", "MessageId", "Mode", "Pid", "Success", "NegativeResponseCode", "Payload", "Value", });
           internal_static_openxc_DynamicField_descriptor =
-            getDescriptor().getMessageTypes().get(9);
+            getDescriptor().getMessageTypes().get(10);
           internal_static_openxc_DynamicField_fieldAccessorTable = new
             com.google.protobuf.GeneratedMessage.FieldAccessorTable(
               internal_static_openxc_DynamicField_descriptor,
               new java.lang.String[] { "Type", "StringValue", "NumericValue", "BooleanValue", });
           internal_static_openxc_TranslatedMessage_descriptor =
-            getDescriptor().getMessageTypes().get(10);
+            getDescriptor().getMessageTypes().get(11);
           internal_static_openxc_TranslatedMessage_fieldAccessorTable = new
             com.google.protobuf.GeneratedMessage.FieldAccessorTable(
               internal_static_openxc_TranslatedMessage_descriptor,
diff --git a/gen/python/openxc_pb2.py b/gen/python/openxc_pb2.py
index 63f7a650..5488b5bb 100644
--- a/gen/python/openxc_pb2.py
+++ b/gen/python/openxc_pb2.py
@@ -13,7 +13,7 @@ from google.protobuf import descriptor_pb2
 DESCRIPTOR = _descriptor.FileDescriptor(
   name='openxc.proto',
   package='openxc',
-  serialized_pb='\n\x0copenxc.proto\x12\x06openxc\"\x94\x03\n\x0eVehicleMessage\x12)\n\x04type\x18\x01 \x01(\x0e\x32\x1b.openxc.VehicleMessage.Type\x12\'\n\x0braw_message\x18\x02 \x01(\x0b\x32\x12.openxc.RawMessage\x12\x35\n\x12translated_message\x18\x03 \x01(\x0b\x32\x19.openxc.TranslatedMessage\x12\x37\n\x13\x64iagnostic_response\x18\x04 \x01(\x0b\x32\x1a.openxc.DiagnosticResponse\x12/\n\x0f\x63ontrol_command\x18\x05 \x01(\x0b\x32\x16.openxc.ControlCommand\x12\x31\n\x10\x63ommand_response\x18\x06 \x01(\x0b\x32\x17.openxc.CommandResponse\"Z\n\x04Type\x12\x07\n\x03RAW\x10\x01\x12\x0e\n\nTRANSLATED\x10\x02\x12\x0e\n\nDIAGNOSTIC\x10\x03\x12\x13\n\x0f\x43ONTROL_COMMAND\x10\x04\x12\x14\n\x10\x43OMMAND_RESPONSE\x10\x05\";\n\nRawMessage\x12\x0b\n\x03\x62us\x18\x01 \x01(\x05\x12\x12\n\nmessage_id\x18\x02 \x01(\r\x12\x0c\n\x04\x64\x61ta\x18\x03 \x01(\x0c\"\xf6\x02\n\x0e\x43ontrolCommand\x12)\n\x04type\x18\x01 \x01(\x0e\x32\x1b.openxc.ControlCommand.Type\x12<\n\x12\x64iagnostic_request\x18\x02 \x01(\x0b\x32 .openxc.DiagnosticControlCommand\x12G\n\x18passthrough_mode_request\x18\x03 \x01(\x0b\x32%.openxc.PassthroughModeControlCommand\x12O\n acceptance_filter_bypass_command\x18\x04 \x01(\x0b\x32%.openxc.AcceptanceFilterBypassCommand\"a\n\x04Type\x12\x0b\n\x07VERSION\x10\x01\x12\r\n\tDEVICE_ID\x10\x02\x12\x0e\n\nDIAGNOSTIC\x10\x03\x12\x0f\n\x0bPASSTHROUGH\x10\x04\x12\x1c\n\x18\x41\x43\x43\x45PTANCE_FILTER_BYPASS\x10\x05\"\x9e\x01\n\x18\x44iagnosticControlCommand\x12*\n\x07request\x18\x01 \x01(\x0b\x32\x19.openxc.DiagnosticRequest\x12\x37\n\x06\x61\x63tion\x18\x02 \x01(\x0e\x32\'.openxc.DiagnosticControlCommand.Action\"\x1d\n\x06\x41\x63tion\x12\x07\n\x03\x41\x44\x44\x10\x01\x12\n\n\x06\x43\x41NCEL\x10\x02\"=\n\x1dPassthroughModeControlCommand\x12\x0b\n\x03\x62us\x18\x01 \x01(\x05\x12\x0f\n\x07\x65nabled\x18\x02 \x01(\x08\"<\n\x1d\x41\x63\x63\x65ptanceFilterBypassCommand\x12\x0b\n\x03\x62us\x18\x01 \x01(\x05\x12\x0e\n\x06\x62ypass\x18\x02 \x01(\x08\"]\n\x0f\x43ommandResponse\x12)\n\x04type\x18\x01 \x01(\x0e\x32\x1b.openxc.ControlCommand.Type\x12\x0f\n\x07message\x18\x02 \x01(\t\x12\x0e\n\x06status\x18\x03 \x01(\x08\"\xfd\x01\n\x11\x44iagnosticRequest\x12\x0b\n\x03\x62us\x18\x01 \x01(\x05\x12\x12\n\nmessage_id\x18\x02 \x01(\r\x12\x0c\n\x04mode\x18\x03 \x01(\r\x12\x0b\n\x03pid\x18\x04 \x01(\r\x12\x0f\n\x07payload\x18\x05 \x01(\x0c\x12\x1a\n\x12multiple_responses\x18\x06 \x01(\x08\x12\x11\n\tfrequency\x18\x07 \x01(\x01\x12\x0c\n\x04name\x18\x08 \x01(\t\x12;\n\x0c\x64\x65\x63oded_type\x18\t \x01(\x0e\x32%.openxc.DiagnosticRequest.DecodedType\"!\n\x0b\x44\x65\x63odedType\x12\x08\n\x04NONE\x10\x01\x12\x08\n\x04OBD2\x10\x02\"\xa1\x01\n\x12\x44iagnosticResponse\x12\x0b\n\x03\x62us\x18\x01 \x01(\x05\x12\x12\n\nmessage_id\x18\x02 \x01(\r\x12\x0c\n\x04mode\x18\x03 \x01(\r\x12\x0b\n\x03pid\x18\x04 \x01(\r\x12\x0f\n\x07success\x18\x05 \x01(\x08\x12\x1e\n\x16negative_response_code\x18\x06 \x01(\r\x12\x0f\n\x07payload\x18\x07 \x01(\x0c\x12\r\n\x05value\x18\x08 \x01(\x01\"\xa2\x01\n\x0c\x44ynamicField\x12\'\n\x04type\x18\x01 \x01(\x0e\x32\x19.openxc.DynamicField.Type\x12\x14\n\x0cstring_value\x18\x02 \x01(\t\x12\x15\n\rnumeric_value\x18\x03 \x01(\x01\x12\x15\n\rboolean_value\x18\x04 \x01(\x08\"%\n\x04Type\x12\n\n\x06STRING\x10\x01\x12\x07\n\x03NUM\x10\x02\x12\x08\n\x04\x42OOL\x10\x03\"\xf7\x01\n\x11TranslatedMessage\x12,\n\x04type\x18\x01 \x01(\x0e\x32\x1e.openxc.TranslatedMessage.Type\x12\x0c\n\x04name\x18\x02 \x01(\t\x12#\n\x05value\x18\x03 \x01(\x0b\x32\x14.openxc.DynamicField\x12#\n\x05\x65vent\x18\x04 \x01(\x0b\x32\x14.openxc.DynamicField\"\\\n\x04Type\x12\n\n\x06STRING\x10\x01\x12\x07\n\x03NUM\x10\x02\x12\x08\n\x04\x42OOL\x10\x03\x12\x12\n\x0e\x45VENTED_STRING\x10\x04\x12\x0f\n\x0b\x45VENTED_NUM\x10\x05\x12\x10\n\x0c\x45VENTED_BOOL\x10\x06\x42\x1c\n\ncom.openxcB\x0e\x42inaryMessages')
+  serialized_pb='\n\x0copenxc.proto\x12\x06openxc\"\x94\x03\n\x0eVehicleMessage\x12)\n\x04type\x18\x01 \x01(\x0e\x32\x1b.openxc.VehicleMessage.Type\x12\'\n\x0braw_message\x18\x02 \x01(\x0b\x32\x12.openxc.RawMessage\x12\x35\n\x12translated_message\x18\x03 \x01(\x0b\x32\x19.openxc.TranslatedMessage\x12\x37\n\x13\x64iagnostic_response\x18\x04 \x01(\x0b\x32\x1a.openxc.DiagnosticResponse\x12/\n\x0f\x63ontrol_command\x18\x05 \x01(\x0b\x32\x16.openxc.ControlCommand\x12\x31\n\x10\x63ommand_response\x18\x06 \x01(\x0b\x32\x17.openxc.CommandResponse\"Z\n\x04Type\x12\x07\n\x03RAW\x10\x01\x12\x0e\n\nTRANSLATED\x10\x02\x12\x0e\n\nDIAGNOSTIC\x10\x03\x12\x13\n\x0f\x43ONTROL_COMMAND\x10\x04\x12\x14\n\x10\x43OMMAND_RESPONSE\x10\x05\";\n\nRawMessage\x12\x0b\n\x03\x62us\x18\x01 \x01(\x05\x12\x12\n\nmessage_id\x18\x02 \x01(\r\x12\x0c\n\x04\x64\x61ta\x18\x03 \x01(\x0c\"\xc8\x03\n\x0e\x43ontrolCommand\x12)\n\x04type\x18\x01 \x01(\x0e\x32\x1b.openxc.ControlCommand.Type\x12<\n\x12\x64iagnostic_request\x18\x02 \x01(\x0b\x32 .openxc.DiagnosticControlCommand\x12G\n\x18passthrough_mode_request\x18\x03 \x01(\x0b\x32%.openxc.PassthroughModeControlCommand\x12O\n acceptance_filter_bypass_command\x18\x04 \x01(\x0b\x32%.openxc.AcceptanceFilterBypassCommand\x12<\n\x16message_format_command\x18\x05 \x01(\x0b\x32\x1c.openxc.MessageFormatCommand\"u\n\x04Type\x12\x0b\n\x07VERSION\x10\x01\x12\r\n\tDEVICE_ID\x10\x02\x12\x0e\n\nDIAGNOSTIC\x10\x03\x12\x0f\n\x0bPASSTHROUGH\x10\x04\x12\x1c\n\x18\x41\x43\x43\x45PTANCE_FILTER_BYPASS\x10\x05\x12\x12\n\x0eMESSAGE_FORMAT\x10\x06\"\x9e\x01\n\x18\x44iagnosticControlCommand\x12*\n\x07request\x18\x01 \x01(\x0b\x32\x19.openxc.DiagnosticRequest\x12\x37\n\x06\x61\x63tion\x18\x02 \x01(\x0e\x32\'.openxc.DiagnosticControlCommand.Action\"\x1d\n\x06\x41\x63tion\x12\x07\n\x03\x41\x44\x44\x10\x01\x12\n\n\x06\x43\x41NCEL\x10\x02\"=\n\x1dPassthroughModeControlCommand\x12\x0b\n\x03\x62us\x18\x01 \x01(\x05\x12\x0f\n\x07\x65nabled\x18\x02 \x01(\x08\"<\n\x1d\x41\x63\x63\x65ptanceFilterBypassCommand\x12\x0b\n\x03\x62us\x18\x01 \x01(\x05\x12\x0e\n\x06\x62ypass\x18\x02 \x01(\x08\"\x86\x01\n\x14MessageFormatCommand\x12\x0b\n\x03\x62us\x18\x01 \x01(\x05\x12:\n\x06\x66ormat\x18\x02 \x01(\x0e\x32*.openxc.MessageFormatCommand.MessageFormat\"%\n\rMessageFormat\x12\x08\n\x04JSON\x10\x01\x12\n\n\x06\x42INARY\x10\x02\"]\n\x0f\x43ommandResponse\x12)\n\x04type\x18\x01 \x01(\x0e\x32\x1b.openxc.ControlCommand.Type\x12\x0f\n\x07message\x18\x02 \x01(\t\x12\x0e\n\x06status\x18\x03 \x01(\x08\"\xfd\x01\n\x11\x44iagnosticRequest\x12\x0b\n\x03\x62us\x18\x01 \x01(\x05\x12\x12\n\nmessage_id\x18\x02 \x01(\r\x12\x0c\n\x04mode\x18\x03 \x01(\r\x12\x0b\n\x03pid\x18\x04 \x01(\r\x12\x0f\n\x07payload\x18\x05 \x01(\x0c\x12\x1a\n\x12multiple_responses\x18\x06 \x01(\x08\x12\x11\n\tfrequency\x18\x07 \x01(\x01\x12\x0c\n\x04name\x18\x08 \x01(\t\x12;\n\x0c\x64\x65\x63oded_type\x18\t \x01(\x0e\x32%.openxc.DiagnosticRequest.DecodedType\"!\n\x0b\x44\x65\x63odedType\x12\x08\n\x04NONE\x10\x01\x12\x08\n\x04OBD2\x10\x02\"\xa1\x01\n\x12\x44iagnosticResponse\x12\x0b\n\x03\x62us\x18\x01 \x01(\x05\x12\x12\n\nmessage_id\x18\x02 \x01(\r\x12\x0c\n\x04mode\x18\x03 \x01(\r\x12\x0b\n\x03pid\x18\x04 \x01(\r\x12\x0f\n\x07success\x18\x05 \x01(\x08\x12\x1e\n\x16negative_response_code\x18\x06 \x01(\r\x12\x0f\n\x07payload\x18\x07 \x01(\x0c\x12\r\n\x05value\x18\x08 \x01(\x01\"\xa2\x01\n\x0c\x44ynamicField\x12\'\n\x04type\x18\x01 \x01(\x0e\x32\x19.openxc.DynamicField.Type\x12\x14\n\x0cstring_value\x18\x02 \x01(\t\x12\x15\n\rnumeric_value\x18\x03 \x01(\x01\x12\x15\n\rboolean_value\x18\x04 \x01(\x08\"%\n\x04Type\x12\n\n\x06STRING\x10\x01\x12\x07\n\x03NUM\x10\x02\x12\x08\n\x04\x42OOL\x10\x03\"\xf7\x01\n\x11TranslatedMessage\x12,\n\x04type\x18\x01 \x01(\x0e\x32\x1e.openxc.TranslatedMessage.Type\x12\x0c\n\x04name\x18\x02 \x01(\t\x12#\n\x05value\x18\x03 \x01(\x0b\x32\x14.openxc.DynamicField\x12#\n\x05\x65vent\x18\x04 \x01(\x0b\x32\x14.openxc.DynamicField\"\\\n\x04Type\x12\n\n\x06STRING\x10\x01\x12\x07\n\x03NUM\x10\x02\x12\x08\n\x04\x42OOL\x10\x03\x12\x12\n\x0e\x45VENTED_STRING\x10\x04\x12\x0f\n\x0b\x45VENTED_NUM\x10\x05\x12\x10\n\x0c\x45VENTED_BOOL\x10\x06\x42\x1c\n\ncom.openxcB\x0e\x42inaryMessages')
 
 
 
@@ -76,11 +76,15 @@ _CONTROLCOMMAND_TYPE = _descriptor.EnumDescriptor(
       name='ACCEPTANCE_FILTER_BYPASS', index=4, number=5,
       options=None,
       type=None),
+    _descriptor.EnumValueDescriptor(
+      name='MESSAGE_FORMAT', index=5, number=6,
+      options=None,
+      type=None),
   ],
   containing_type=None,
   options=None,
-  serialized_start=770,
-  serialized_end=867,
+  serialized_start=832,
+  serialized_end=949,
 )
 
 _DIAGNOSTICCONTROLCOMMAND_ACTION = _descriptor.EnumDescriptor(
@@ -100,8 +104,29 @@ _DIAGNOSTICCONTROLCOMMAND_ACTION = _descriptor.EnumDescriptor(
   ],
   containing_type=None,
   options=None,
-  serialized_start=999,
-  serialized_end=1028,
+  serialized_start=1081,
+  serialized_end=1110,
+)
+
+_MESSAGEFORMATCOMMAND_MESSAGEFORMAT = _descriptor.EnumDescriptor(
+  name='MessageFormat',
+  full_name='openxc.MessageFormatCommand.MessageFormat',
+  filename=None,
+  file=DESCRIPTOR,
+  values=[
+    _descriptor.EnumValueDescriptor(
+      name='JSON', index=0, number=1,
+      options=None,
+      type=None),
+    _descriptor.EnumValueDescriptor(
+      name='BINARY', index=1, number=2,
+      options=None,
+      type=None),
+  ],
+  containing_type=None,
+  options=None,
+  serialized_start=1335,
+  serialized_end=1372,
 )
 
 _DIAGNOSTICREQUEST_DECODEDTYPE = _descriptor.EnumDescriptor(
@@ -121,8 +146,8 @@ _DIAGNOSTICREQUEST_DECODEDTYPE = _descriptor.EnumDescriptor(
   ],
   containing_type=None,
   options=None,
-  serialized_start=1471,
-  serialized_end=1504,
+  serialized_start=1690,
+  serialized_end=1723,
 )
 
 _DYNAMICFIELD_TYPE = _descriptor.EnumDescriptor(
@@ -146,8 +171,8 @@ _DYNAMICFIELD_TYPE = _descriptor.EnumDescriptor(
   ],
   containing_type=None,
   options=None,
-  serialized_start=1796,
-  serialized_end=1833,
+  serialized_start=2015,
+  serialized_end=2052,
 )
 
 _TRANSLATEDMESSAGE_TYPE = _descriptor.EnumDescriptor(
@@ -183,8 +208,8 @@ _TRANSLATEDMESSAGE_TYPE = _descriptor.EnumDescriptor(
   ],
   containing_type=None,
   options=None,
-  serialized_start=1991,
-  serialized_end=2083,
+  serialized_start=2210,
+  serialized_end=2302,
 )
 
 
@@ -329,6 +354,13 @@ _CONTROLCOMMAND = _descriptor.Descriptor(
       message_type=None, enum_type=None, containing_type=None,
       is_extension=False, extension_scope=None,
       options=None),
+    _descriptor.FieldDescriptor(
+      name='message_format_command', full_name='openxc.ControlCommand.message_format_command', index=4,
+      number=5, type=11, cpp_type=10, label=1,
+      has_default_value=False, default_value=None,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
   ],
   extensions=[
   ],
@@ -340,7 +372,7 @@ _CONTROLCOMMAND = _descriptor.Descriptor(
   is_extendable=False,
   extension_ranges=[],
   serialized_start=493,
-  serialized_end=867,
+  serialized_end=949,
 )
 
 
@@ -375,8 +407,8 @@ _DIAGNOSTICCONTROLCOMMAND = _descriptor.Descriptor(
   options=None,
   is_extendable=False,
   extension_ranges=[],
-  serialized_start=870,
-  serialized_end=1028,
+  serialized_start=952,
+  serialized_end=1110,
 )
 
 
@@ -410,8 +442,8 @@ _PASSTHROUGHMODECONTROLCOMMAND = _descriptor.Descriptor(
   options=None,
   is_extendable=False,
   extension_ranges=[],
-  serialized_start=1030,
-  serialized_end=1091,
+  serialized_start=1112,
+  serialized_end=1173,
 )
 
 
@@ -445,8 +477,44 @@ _ACCEPTANCEFILTERBYPASSCOMMAND = _descriptor.Descriptor(
   options=None,
   is_extendable=False,
   extension_ranges=[],
-  serialized_start=1093,
-  serialized_end=1153,
+  serialized_start=1175,
+  serialized_end=1235,
+)
+
+
+_MESSAGEFORMATCOMMAND = _descriptor.Descriptor(
+  name='MessageFormatCommand',
+  full_name='openxc.MessageFormatCommand',
+  filename=None,
+  file=DESCRIPTOR,
+  containing_type=None,
+  fields=[
+    _descriptor.FieldDescriptor(
+      name='bus', full_name='openxc.MessageFormatCommand.bus', index=0,
+      number=1, type=5, cpp_type=1, label=1,
+      has_default_value=False, default_value=0,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+    _descriptor.FieldDescriptor(
+      name='format', full_name='openxc.MessageFormatCommand.format', index=1,
+      number=2, type=14, cpp_type=8, label=1,
+      has_default_value=False, default_value=1,
+      message_type=None, enum_type=None, containing_type=None,
+      is_extension=False, extension_scope=None,
+      options=None),
+  ],
+  extensions=[
+  ],
+  nested_types=[],
+  enum_types=[
+    _MESSAGEFORMATCOMMAND_MESSAGEFORMAT,
+  ],
+  options=None,
+  is_extendable=False,
+  extension_ranges=[],
+  serialized_start=1238,
+  serialized_end=1372,
 )
 
 
@@ -487,8 +555,8 @@ _COMMANDRESPONSE = _descriptor.Descriptor(
   options=None,
   is_extendable=False,
   extension_ranges=[],
-  serialized_start=1155,
-  serialized_end=1248,
+  serialized_start=1374,
+  serialized_end=1467,
 )
 
 
@@ -572,8 +640,8 @@ _DIAGNOSTICREQUEST = _descriptor.Descriptor(
   options=None,
   is_extendable=False,
   extension_ranges=[],
-  serialized_start=1251,
-  serialized_end=1504,
+  serialized_start=1470,
+  serialized_end=1723,
 )
 
 
@@ -649,8 +717,8 @@ _DIAGNOSTICRESPONSE = _descriptor.Descriptor(
   options=None,
   is_extendable=False,
   extension_ranges=[],
-  serialized_start=1507,
-  serialized_end=1668,
+  serialized_start=1726,
+  serialized_end=1887,
 )
 
 
@@ -699,8 +767,8 @@ _DYNAMICFIELD = _descriptor.Descriptor(
   options=None,
   is_extendable=False,
   extension_ranges=[],
-  serialized_start=1671,
-  serialized_end=1833,
+  serialized_start=1890,
+  serialized_end=2052,
 )
 
 
@@ -749,8 +817,8 @@ _TRANSLATEDMESSAGE = _descriptor.Descriptor(
   options=None,
   is_extendable=False,
   extension_ranges=[],
-  serialized_start=1836,
-  serialized_end=2083,
+  serialized_start=2055,
+  serialized_end=2302,
 )
 
 _VEHICLEMESSAGE.fields_by_name['type'].enum_type = _VEHICLEMESSAGE_TYPE
@@ -764,10 +832,13 @@ _CONTROLCOMMAND.fields_by_name['type'].enum_type = _CONTROLCOMMAND_TYPE
 _CONTROLCOMMAND.fields_by_name['diagnostic_request'].message_type = _DIAGNOSTICCONTROLCOMMAND
 _CONTROLCOMMAND.fields_by_name['passthrough_mode_request'].message_type = _PASSTHROUGHMODECONTROLCOMMAND
 _CONTROLCOMMAND.fields_by_name['acceptance_filter_bypass_command'].message_type = _ACCEPTANCEFILTERBYPASSCOMMAND
+_CONTROLCOMMAND.fields_by_name['message_format_command'].message_type = _MESSAGEFORMATCOMMAND
 _CONTROLCOMMAND_TYPE.containing_type = _CONTROLCOMMAND;
 _DIAGNOSTICCONTROLCOMMAND.fields_by_name['request'].message_type = _DIAGNOSTICREQUEST
 _DIAGNOSTICCONTROLCOMMAND.fields_by_name['action'].enum_type = _DIAGNOSTICCONTROLCOMMAND_ACTION
 _DIAGNOSTICCONTROLCOMMAND_ACTION.containing_type = _DIAGNOSTICCONTROLCOMMAND;
+_MESSAGEFORMATCOMMAND.fields_by_name['format'].enum_type = _MESSAGEFORMATCOMMAND_MESSAGEFORMAT
+_MESSAGEFORMATCOMMAND_MESSAGEFORMAT.containing_type = _MESSAGEFORMATCOMMAND;
 _COMMANDRESPONSE.fields_by_name['type'].enum_type = _CONTROLCOMMAND_TYPE
 _DIAGNOSTICREQUEST.fields_by_name['decoded_type'].enum_type = _DIAGNOSTICREQUEST_DECODEDTYPE
 _DIAGNOSTICREQUEST_DECODEDTYPE.containing_type = _DIAGNOSTICREQUEST;
@@ -783,6 +854,7 @@ DESCRIPTOR.message_types_by_name['ControlCommand'] = _CONTROLCOMMAND
 DESCRIPTOR.message_types_by_name['DiagnosticControlCommand'] = _DIAGNOSTICCONTROLCOMMAND
 DESCRIPTOR.message_types_by_name['PassthroughModeControlCommand'] = _PASSTHROUGHMODECONTROLCOMMAND
 DESCRIPTOR.message_types_by_name['AcceptanceFilterBypassCommand'] = _ACCEPTANCEFILTERBYPASSCOMMAND
+DESCRIPTOR.message_types_by_name['MessageFormatCommand'] = _MESSAGEFORMATCOMMAND
 DESCRIPTOR.message_types_by_name['CommandResponse'] = _COMMANDRESPONSE
 DESCRIPTOR.message_types_by_name['DiagnosticRequest'] = _DIAGNOSTICREQUEST
 DESCRIPTOR.message_types_by_name['DiagnosticResponse'] = _DIAGNOSTICRESPONSE
@@ -825,6 +897,12 @@ class AcceptanceFilterBypassCommand(_message.Message):
 
   # @@protoc_insertion_point(class_scope:openxc.AcceptanceFilterBypassCommand)
 
+class MessageFormatCommand(_message.Message):
+  __metaclass__ = _reflection.GeneratedProtocolMessageType
+  DESCRIPTOR = _MESSAGEFORMATCOMMAND
+
+  # @@protoc_insertion_point(class_scope:openxc.MessageFormatCommand)
+
 class CommandResponse(_message.Message):
   __metaclass__ = _reflection.GeneratedProtocolMessageType
   DESCRIPTOR = _COMMANDRESPONSE
diff --git a/openxc.proto b/openxc.proto
index c7f75913..97a6ebb6 100644
--- a/openxc.proto
+++ b/openxc.proto
@@ -28,12 +28,14 @@ message ControlCommand {
         DIAGNOSTIC = 3;
         PASSTHROUGH = 4;
         ACCEPTANCE_FILTER_BYPASS = 5;
+        MESSAGE_FORMAT = 6;
     }
 
     optional Type type = 1;
     optional DiagnosticControlCommand diagnostic_request = 2;
     optional PassthroughModeControlCommand passthrough_mode_request = 3;
     optional AcceptanceFilterBypassCommand acceptance_filter_bypass_command = 4;
+    optional MessageFormatCommand message_format_command = 5;
 }
 
 message DiagnosticControlCommand {
@@ -53,6 +55,16 @@ message AcceptanceFilterBypassCommand {
     optional bool bypass = 2;
 }
 
+message MessageFormatCommand {
+    enum MessageFormat {
+        JSON = 1;
+        BINARY = 2;
+    }
+
+    optional int32 bus = 1;
+    optional MessageFormat format = 2;
+}
+
 message CommandResponse {
     optional ControlCommand.Type type = 1;
     optional string message = 2;