IoT Fleetwise - Adding support for multiple PID's in the dbc file

Question

We've a requirement where multiple PID's of the vehicle diagnostic data from the vehicle has to be supported.

But when we try adding more than one PID under a BO in dbc file, it gives us below error -

"An error occurred (ValidationException) when calling the ImportDecoderManifest operation: Could not parse the DBC file(s) for network interface 1. Following failures were observed [Failed to parse signal line     SG_ S1 m1M : 23|8@0+ (1,0) [0|255] "" Vector__XXX for messageId 2024 for network interface 1]"

Do you've an example of OBD2 dbc file which has support for multiple PID's and is supported by Fleetwise ?

Below is the content of the dbc file we are using

VERSION "1.0"

NS_ :
	NS_DESC_
	CM_
	BA_DEF_
	BA_
	VAL_
	CAT_DEF_
	CAT_
	FILTER
	BA_DEF_DEF_
	EV_DATA_
	ENVVAR_DATA_
	SGTYPE_
	SGTYPE_VAL_
	BA_DEF_SGTYPE_
	BA_SGTYPE_
	SIG_TYPE_REF_
	VAL_TABLE_
	SIG_GROUP_
	SIG_VALTYPE_
	SIGTYPE_VALTYPE_
	BO_TX_BU_
	BA_DEF_REL_
	BA_REL_
	BA_DEF_DEF_REL_
	BU_SG_REL_
	BU_EV_REL_
	BU_BO_REL_

BS_:

BU_:

BO_ 2024  OBD2: 8 Vector__XXX

SG_ S1_PID_0C_EngineSpeed m12 : 31|16@0+ (0.25,0) [0|16383.75] "rpm" Vector__XXX
    SG_ S1_PID_0D_VehicleSpeed m13 : 31|8@0+ (1,0) [0|255] "km/h" Vector__XXX
    SG_ S1 m1M : 23|8@0+ (1,0) [0|255] "" Vector__XXX
    SG_ Service M : 11|4@0+ (1,0) [0|15] "" Vector__XXX

BA_DEF_ SG_  "SignalType" STRING ;
BA_DEF_ SG_  "SignalLongName" STRING ;
BA_DEF_ BO_  "GenMsgCycleTime" INT 0 10000;
BA_DEF_DEF_  "SignalType" "";
BA_DEF_DEF_  "SignalLongName" "";
BA_DEF_DEF_  "GenMsgCycleTime" 0;
BA_ "GenMsgCycleTime" BO_ 2024  50;
BA_ "GenMsgCycleTime" BO_ 2025  50;
SG_MUL_VAL_ 2024 S1_PID_0C_EngineSpeed S1 12-12;
SG_MUL_VAL_ 2024 S1_PID_0D_VehicleSpeed S1 13-13;
SG_MUL_VAL_ 2024 S1 Service 1-1

Answer

Hello Kamalnath,

The error message you're encountering indicates that there is an issue with the syntax or format of your DBC (Database Container) file, specifically related to the definition of signals and the assignment of Multiplex values (like S1) within a message (BO_).

The issue appears to be in your DBC file's definition of signal lines. In the DBC file format, each signal line (SG_) should be defined with specific attributes, such as start bit, length, byte order, and more. The error message suggests that there is a problem with the signal definition for "S1_PID_0C_EngineSpeed," "S1_PID_0D_VehicleSpeed," and "S1 Service."

Here's a corrected example for the signal definitions in your DBC file:

```dbc
SG_ S1_PID_0C_EngineSpeed : 31|16@0+ (0.25,0) [0|16383.75] "rpm" Vector__XXX
SG_ S1_PID_0D_VehicleSpeed : 23|8@0+ (1,0) [0|255] "km/h" Vector__XXX
SG_ S1_Service : 11|4@0+ (1,0) [0|15] "" Vector__XXX
```

In the corrected lines above, I removed the multiplex value "m12," "m13," and "M" from the signal names because multiplexing values should not be part of the signal name in the DBC file. Instead, you should define the multiplexing relationship in the multiplexing settings section of the DBC file.

For example, in the multiplexing settings section of your DBC file, you can define how signals are multiplexed within a message (BO_). Assuming you want all three signals (S1_PID_0C_EngineSpeed, S1_PID_0D_VehicleSpeed, and S1_Service) to be multiplexed using the same "S1" multiplexer value, you can define it like this:

```dbc
SG_MUL_VAL_ 2024 S1_PID_0C_EngineSpeed S1 12-12;
SG_MUL_VAL_ 2024 S1_PID_0D_VehicleSpeed S1 13-13;
SG_MUL_VAL_ 2024 S1_Service S1 1-1;
```

In this example, the multiplexing value "S1" is associated with all three signals within message 2024 (BO_ 2024), allowing you to represent multiple PIDs under a single message with the same multiplexing value.

Make sure to adjust the DBC file accordingly to match your specific use case and multiplexing requirements.

Please give a thumbs up if my suggestion helps

IoT Fleetwise - Adding support for multiple PID's in the dbc file

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