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2. COMMUNICATION INTERFACE
2.10: Error processing
No response error
In the following cases, message is ignored and no response is sent.
1. When message transmission error (overrun, framing, parity, CRC or LRC) is detected.
2. When slave address in message is not for receiving device.
3. When message data interval is too long.
RTU...When less than 9600bps: 20msec or more
When over 9600bps: 5msec or more
ASCII...1sec or more
4. When transmission parameters are not in agreement.
5. When receiving message exceeds maximum allowable bytes.
Response error
When master message contains no error, but the following problems (see table below) occur, a
code signifying error content is sent in response as an "error message".
Slave address
Function code
Function code + 80H
Function code + 80H
Error codes
CRC (L)
03
83H
CRC (H)
04
84H
06
86H
2.11: Transmission error codes
Transmission error codes are as follows:
Error Codes
Description
01H
Function code error
Irregular/incorrect function code is received
02H
Relative number (reference number) error
Irregular/incorrect start number or setting value number is received
03H
Incorrect number of data pieces
･
Number of data exceeds the specified number for data to be transmitted
in response to received message
･
The number of request is 0
･
Number of specified data received and actual number of data are not in
agreement
11H
Setting value out of range
Setting value is outside the range defined in the reference table
12H
Setting not available
