CAN J1939 Set Request Messages

Set Commands

The following Set requests have been implemented in J1939 based application examples. Users can modify provided requests and/or implement their own unique commands.

Set Commands

Request	PF (dec)	PS (dec)	PGN	Payload Length (bytes)	Purpose
Save Configuration	255	81	65361	3	Save all configuration data to non-volatile memory
Reset Algorithm	255	80	65360	3	Reset algorithm to initial conditions
Mag Alignment	255	94	65374	2	Mag alignment and status request
Set Packet Rate Divider	255	85	65365	2	Set rate dividers to increase/decrease rate packets are set
Set Data Packet Type(s)	255	86	65366	2	Select packet types to be sent periodically
Set Digital Filters Cutoff Frequencies	255	87	65367	3	Set LPF cutoff frequency for rate sensors and accelerometers
Set Orientation	255	88	65368	3	Set unit orientation
Set Lever Arm (TBD)	255	95	65375	8	Set unit Lever Arm (where applicable)
Set Bank of PS Numbers for Bank0	255	240	65520	8	Reconfigure PS numbers for set requests
Set Bank of PS Numbers for Bank1	255	241	65521	8	Reconfigure PS numbers for set requests

Note

PS values for all but the “Set Bank of PS Numbers for Bank0/Bank1” Set Commands can be changed by the the commands “Set Bank of PS Numbers” (see below). Updated values can be saved in nonvolatile memory and will be active upon following system restart/power-up. Provided in the table PS values are default values.

Save Configuration

The next table provides the descriptions of the payload fields of the command and response messages.

Save Configuration Request/Response Payload Fields

Byte	Description/Values
0	Type: 0 = Request, 1 = Response
1	Destination Address
2	Response: 0 = Fail, 1 = Succeed

Reset Algorithm

The following table provides the descriptions of the payload fields of the command and response messages.

Reset Algorithm Request/Response Payload Fields

Byte	Description/Values
0	Type: 0 = Request, 1 = Response
1	Destination Address
2	Response: 0 = Fail, 1 = Succeed

Mag Alignment (INS Application Example)

The following tables provides the descriptions of the payload fields of the command and response messages.

Mag Alignment Request Payload Fields

Byte	Description/Values
0	Destination Address
1	Commands: 0 - Status Request 1 - Start Alignment 5 - Confirm and Save

Payload Fields of 64 bit Response

Bits	Description	Value
bits 0:7	Command	0 - Status request, 1 - Start alignment
bit 8:15	Alignment State	0 - Idle 12 - Alignment in process 11, 13 - Data Collection complete
bit 16:27	Estimated Hard Iron X Bias, Gauss	-8 G to +8 G , scale 1/256 G/bit, offset -8G
bits 28:39	Estimated Hard ron Y Bias, Gauss	-8 G to +8 G , scale 1/256 G/bit, offset -8G
bits 40:49	Estimated Soft Iron Ratio	0 to 1 1/1024 per Lsb
bits 50:63	Estimated Soft Iron Angle	-3.14 to 3.14 RAD, scale 0.0015339, offset -3.14159

Set Packet Rate Divider

The following table provides the values of the packet rate divider response payload

Set Packet Rate Divider Request/Response Payload Fields

Byte	Description	Byte Value
0	Destination Address	Unique
1	Packet Divider Value	Byte Value - Packet Broadcast Rate (Hz) 0 - Quiet Mode - no broadcast 1 - 100 (default) 2 - 50 4 - 25 5 - 20 10 (0x0a) - 10 20 (0x14) - 5 25 (0x19) - 4 50 (0x32) - 2

Set Periodic Data Packet Type(s)

The following table provides the Set Data Packet Type(s) payload. Each bit in the request payload enables specific data packet for periodic transmission. Any combination of data packets can be chosen.

Set Data Packet Type(s) Field

Byte	Description	Byte Value
0	Destination Address	Unique
1	Selected Data Packet Type(s) Bitmask (LSB)	Data Packet Type(s) Bitmask: Bit 0 - SSI2 Bit 1 - Angular Rate Bit 2 - Acceleration Bit 3 - Magnetometer
2	Selected Data Packet Type(s) Bitmask (MSB)	Reserved

Set Digital Filter Cutoff Frequencies

The following table provides descriptions of the request payload

Digital Filter Cutoff Frequencies Request Payload

Payload Byte	Description/Values	Values
0	Destination Address	Unique
1	Cutoff Frequencies (Hz) for Angular Rate Sensors	0, 2, 5, 10, 25, 40, or 50
2	Cutoff Frequencies (Hz) for Accelerometer Sensors	0, 2, 5, 10, 25, 40, or 50

Set Orientation

The following table shows the payload layout

Set Orientation Payload Layout

Byte	Meaning	Value
0	Destination Address	Unique
1	Orientation Value (MSB)	see table below
2	Orientation VAlue (LSB)	see table below

The following table provides the orientation values and meanings:

Set Orientation Field Descriptions

Orientation Value	X/Y/Z Axis	Orientation Value(cont)	X/Y/Z Axis
0x0000	+Ux +Uy +Uz (default)	0x00C4	+Uz +Uy -Ux
0x0009	-Ux -Uy +Uz	0x00CD	-Uz -Uy -Ux
0x0023	-Uy +Ux +Uz	0x00D3	-Uy +Uz -Ux
0x002A	+Uy -Ux +Uz	0x00DA	+Uy -Uz -Ux
0x0041	-Ux +Uy -Uz	0x0111	-Ux +Uz +Uy
0x0048	+Ux -Uy -Uz	0x0118	+Ux -Uz +Uy
0x0062	+Uy +Ux -Uz	0x0124	+Uz +Ux +Uy
0x006B	-Uy -Ux -Uz	0x012D	-Uz -Ux +Uy
0x0085	-Uz +Uy +Ux	0x0150	+Ux +Uz -Uy
0x008C	+Uz -Uy +Ux	0x0159	-Ux -Uz -Uy
0x0092	+Uy +Uz +Ux	0x0165	-Uz +Ux -Uy
0x009B	-Uy -Uz +Ux	0x016C	+Uz -Ux -Uy

Set Lever Arm (TBD)

The following table shows the payload layout

Set Lever Arm payload

Byte	Description
0	Destination 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

Set Bank of PS Numbers

The following tables provide descriptions of the payload for Bank0 and Bank1 set commands

Set Bank of PS Numbers for Bank0 Payload

Byte	Parameters
0	Destination Address
1	Reset Algorithm PS number
2	Save Configuration PS number
3	Status Request PS number
4	Mag Align Command PS number
5-7	Reserved

Set Bank of PS Numbers for Bank1 Payload

Byte	Parameters
0	Destination Address
1	Set Packet Rate PS number
2	Set Packet Type(s) PS number
3	Set Digital Filer Cutoff Frequencies PS number
4	Set Orientation PS Number
5	Set User Behavior PS Number
6	Set Lever Arm PS Number
7	Reserved