Mitsubishi MELSEC LJ71C24, User Manual

Page: 209 / 428

11 - 23 11 - 23
11 DATA COMMUNICATION USING THE BIDIRECTIONAL PROTOCOL
11.2.4 How to detect and confirm transmission errors
This section explains how to detect and confirm errors that may occur when sending
data to external devices.
The following items are considered as the primary causes of errors that may occur
during data transmission.
Cause of transmission error Reference
A transmission error occurred due to noise. Section 6.2, Section 6.3
A timeout occurred for the no-reception monitoring time (timer 0).
A timeout occurred for the response monitoring time (timer 1).
A timeout occurred for the transmission monitoring time (timer 2).
Data that could not be converted with the ASCII-BIN conversion was detected.
User's Manual (Application)
Designated the transmission data count that exceeded the transmission area size. Section 11.2.2
Simultaneous transmissions occurred. Section 11.3
(1) Confirmation using the sequence program
(a) Detecting a transmission error
The following device and input signal turn ON.
• BIDOUT instruction complete 1
• ERR. occurrence (XE/XF)
(b) Confirming a transmission error
The transmission error code can be checked using the BIDOUT instruction
control data ((S1) + 1).
Or, it can be checked by reading the data transmission result (address:
257
H
/267
H
).
POINT
For details of how to check the error code contents and corrective actions, refer to
Chapter 11.