Table of Contents
Advertisement
4.7 Process of an abnormality
When no reply will be returned
No reply will be returned ignoring the message in the following cases:
①An transmission error (overrun, framing, parity, CRC or LRC) is found in the message.
②The slave address in the message is different from my address.
③Data interval of the message is long.
When RTU is less than 9600bps：20msec or higher
ASCII...1 second or more
④When transmission parameters do not match.
⑤The size of the received message exceeds the acceptable number of bytes.
Replying an error message
When any of the troubles below is detected even though the message from the master does not
contain any errors, a code that describes that error will be returned as an "error message".
The error message format is as follows:
Slave address
Function code+80H
Error code
CRC(L)
CRC(H)
9600bps or more：5msec or higher
Function code
03
04
06
43
4. Operating procedures
Setting external communication
Function code
+80H
83H
84H
86H
Advertisement
Table of Contents
