CAN J1939 Get Request Messages

Get Requests

Get requests are used by other ECUs in the network to retrieve information from the OpenIMU300RI. All Get requests are formed as a Request message as specified earlier. The format and content of the Request message has next format:

Extended header:

PF : 234,
PS : 255,
DLC : 3,
Priority: 6,
PGN : 60159.
Request Payload
Byte Description
0 N/A
1 PF of requested parameter
2 PS of requested parameter

In table below provided list of the parameters which can be requested from ECU, including their PF, PS and payload length of response messages

List of ECU parameters available for Requests
Parameter
PF
(dec)

PS
(dec)
(See note)
Payload Length (bytes)
Software Version 254 218 5
ECU ID 253 197 8
Packet Rate 255 85 2
Packet Type 255 86 3
Digital Cutoff Frequency 255 87 3
Orientation 255 88 3
Lever Arm(TBD) 255 95 8

Note

  • Provided PS values for all but the Get Software Version and Get ECU ID can be changed by the “Set Bank of PS Numbers for Bank1” command. The given values are the default values.
  • In responses values of PF and PS field in extended headers have the same PF+PS values as requested.

Responses to Get Requests

The following table describe the payloads for responses to Get Requests

Software Version Response Payload
Byte Description
0 Major Version Number
1 Minor Version Number
2 Patch Number
3 Stage Number
4 Build Number
ECU ID 64 Bit Response Payload
Bits Contents
bits 0
bit 1:3
bit 4:7
bits 8:14
bits 15
bits 16:23
bits 24:28
bits 29:31
bits 32:42
bits 43:63
Arbitrary Address
Industry Group
Vehicle System Instance
System Bits
Reserved
Function Bits
Function Instance
ECU Bits
Manufacturer code
ID bits
Packet Rate Response Payload
Byte Description
0 Source Address
1 Output Data Rate
Packet Type Response Payload
Byte Description
0 Source Address
1 Packet Types Bitmask (LSB)
2 Packet Types Bitmask (MSB)
Digital Cutoff Frequency Response Payload
Byte Description
0 Source Address
1 Acceleration Cutoff
2 Angular Rate Cutoff
Orientation Response Payload
Byte Description
0 Source Address
1 Orientation Value (MSB)
2 Orientation Value (LSB)
Lever Arm Response Payload (TBD)
Byte Description
0 Source Address
1 reserved
2 Wheel Distance Value (LSB), mm
3 Wheel Distance Value (MSB), mm
4 Lever Arm Bx Value (LSB), mm
5 Lever Arm Bx Value (MSB), mm
6 Lever Arm By Value (LSB), mm
7 Lever Arm By Value (MSB), mm

Note

  • For Orientation, Cutoff Frequencies Packet Type and Packet Rate responses values of parameters will be the same as in the set commands for these parameters.