Message Transmission (sending data to the 1939STB)
The transmission window is divided into three rows. The first row is the internal header information. The second row contains message control information. The third row is the data payload sent with the information.
The first row has 4 bytes. Bytes 1 and 2 are set to 8 and 21 hex. All data is entered in hex. The next two bytes, 3 and 4, are set by the user. Refer to pages 6 and 7 of this manual for help setting theses two bytes. Setting a byte is done by clicking in the box under the label and entering the proper hex value. All values in this row must contain information or the message will be rejected.
The second row contains bytes 5 though 11. These bytes are set by the user. All values are entered in hex. All of the bytes in this row do NOT have to contain data for the message to be accepted.
The last row is the data payload that is transmitted with an SAE-
J1939 message. This row may contain data or left blank.
Message Reception
To receive information from the
NOTE: MicroSoft Visual Basic only allows a buffer of approximately 3K. You must manually clear the Receive Message buffer or you will get a buffer overflow error.
34 | 1939STB4600 Manual | |
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| B&B Electronics Ltd – Westlink Commercial Park – Oranmore, Galway, Ireland – Ph +353 91 792444 | – Fax +353 91 792445 |
