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Byte # | Name | Description |
0 | Packet start (3Ah) | Data packet start |
1 | OpenMATID byte 1 | Contains the low byte of the OpenMAT ID of the sensor to be communicated with. The default value of this ID is 1. The host sends out a GET / SET request to a specific LPMS sensor by using this ID, and the client answers to request also with the same ID. This ID can be adjusted by sending a SET command to the sensor firmware. |
2 | OpenMAT ID byte 2 | High byte of the OpenMAT ID of the sensor. |
3 | Command # byte 1 | Contains the low byte of the command to be performed by the data transmission. |
4 | Command # byte 2 | High byte of the command number. |
5 | Packet data length byte 1 | Contains the low byte of the packet data length to be transmitted in the packet data field. |
6 | Packet data length byte 2 | High byte of the data length to be transmitted. |
x | Packet data(n bytes) | If data length n not equal to zero, x = 6+1, 6+2…6+n. Otherwise x = none. This data field contains the packet data to be transferred with the transmission if the data length not equals to zero, otherwise the data field is empty. |
7+n | LRC byte 1 | The low byte of LRC checksum. To ensure the integrity of the transmitted data the LRC checksum is used. It is calculated in the following way: LRC = sum(OpenMAT ID, Command, Package data length, and packet data byte no. 1 to no. x) The calculated LRC is usually compared with the LRC transmitted from the remote device. If the two LRCs are not equal, and error is reported. |
8+n | LRC byte 2 | High byte of LRC check-sum. |
9+n | Termination byte 1 | 0Dh |
10+n | Termination byte 2 | 0Ah |
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