J1939 Commands
The J1939 protocol is similar to the J1708 protocol.
The message starts with Start of Frame byte 01. The number of control bytes will be 06. The control code for J1939 is 02. The function codes (XX) are as follows:
00=Sets receive function off 01=Sets receive on 02=Transmits a message with data 04=Set mask
19=filter 1 set on 18=filter 1 set off 29=filter 2 set on 28=filter 2 set off 39=filter 3 set on 38=filter 3 set off 49=filter 4 set on 48=filter 4 set off
Function codes are shown in detail below.
Before operating the HDV100A3 in the J1939 mode it is
recommended that the baud rate be set to 115.2kb. This is done by sending the following code: (01, 05, 08, 01, 03, 04, 00, 00 16). After sending this command the baud rate of the sending device (PC) must also be changed.
Because of the difference in baud rates between the J1939 bus and the
Sending any message with a control code of (02) to the J1939 bus stops the operation on the J1708 bus. If you wish to restart operation on the J1708 bus you must send the start J1708 reception message (01, 02, 01, 11, 00, 15). Sending this message stops operation on the J1939 bus.
Function codes 00 and 01, Receive OFF, ON operate together to control a receive register. Sending the command (01, 02, 02, 01, 00, 06) starts reception on the J1939 bus. This command resets the filter mask to all zeros (don’t care). All bus traffic is then received. However, it may not be possible to send all messages to the PC side. Any message that is not serviced before the next message is received will be overwritten by the new message. Sending the command (01, 02, 02, 00, 00, 05) turns off the receiver. It is
HDV100A3 Command & Response | 19 |
B&B Electronics
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