MD30 sends an CRC error acknowledgment message when it detects an error in the CRC checksum.
The CRC error acknowledgment message does not contain data. The message receiver ID, message ID, and message number are set to 0.
To disable CRC error acknowledgments, use parameter 0x11.
Example of request message with CRC error
0xab 0x00 0x01 0x10 0x00 0x00 0x00 0x00 0x00The example request is a GET UNIT ID message with a checksum of 0.
Format of CRC error acknowledgment message
<message start> <message sender ID> <message receiver ID> <message ID> <message number> <data length> <interface version number> <error code> <CRC>| Message field | Offset | Size in bytes | Bytes | Value |
|---|---|---|---|---|
|
Message start |
0 | 1 | 0xab | 0xab |
|
Message sender ID |
1 | 1 | 0x01 | 1 |
|
Message receiver ID |
2 | 1 | 0x00 | 0 |
|
Message ID |
3 | 1 | 0x00 | 0x00 |
|
Message number |
6 | 1 | 0x00 | 0 |
|
Data length |
4 - 5 | 2 | 0x02 0x00 | 2 |
|
Interface version |
7 | 1 | 0x43 | C |
|
Error code |
8 | 1 | 0x01 | 1 = CRC error |
|
CRC |
9 ... 10 | 2 | 0x3b 0xd3 | - |
Example
0xab 0x01 0x00 0x00 0x00 0x02 0x00 0x44 0x01 0xac 0x4aThe example response contains the following information:
- Unit ID: 1
- Client ID: 0
- Message ID: 0x00
- Message number: 0
- Length: 2
- Interface version: D
- Error code: 1 (CRC error)