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5.6 Processing in Abnormal Status
The following response is given when any problem is found in the content of a message from the master unit.
5.6.1 Case of no response
The message is ignored with no response given when
(1) A transmission error (overrun, framing, parity, CRC or LRC) is detected in the message;
(2) The slave address in the message is not the receiver's own address;
(3) Data interval in messages is too long;
28 bits or more in RTU mode
1 second or more in ASCII mode
(4) Transmission parameters are not consistent with those of the receiver;
(5) The bytes of the received message exceeds 512.
Note) When the slave address is "0" in the write function, the message is executed unless any error is
detected in it, but with no response given to it. Since no response is given also when the above error is
detected in the message, whether it is normal or abnormal can not be judged by the response from
this recorder when the slave address is "0".
5.6.2 Response error message
If the following failure is detected in a message from the master unit with no error specified in Section 5.6.1,
the code indicating the error is responded as an "error message".
The error message format is as follows.
Slave address
Function code
Function code + 80H
Function code + 80H
01
81H
Error code
02
82H
CRC(L) 03
83H
CRC(H) 04
84H
05
85H
06
86H
08
88H
16
90H
70
C6H
71
C7H
