Transmission Error Detection And Check Methods - Mitsubishi Electric MELSEC iQ-R Series User Manual

Transmission error detection and check methods

The following explains how to detect and confirm errors that may occur when sending data to target devices.
The possible primary causes of errors during data transmission are shown below.
Cause of transmission error
A timeout occurred for the send monitoring time (timer 2).
The send data quantity exceeding the size that can be stored in the send area
is designated.
Detection/checking of transmission error by a program
■Detecting a transmission error
The following device and input signal turn ON.
• OUTPUT instruction completion device + 1
• 'CH Error occurrence' (XE/XF)
■Checking a transmission error
The transmission error code can be checked using the OUTPUT instruction control data ((S1) + 1).
Or, it can be checked by reading the 'data transmission result' (Un\G599/615).
For details on how to check the error code contents and corrective actions, refer to the following section.
Page 473 Error Code List
Detection/checking of transmission error with module and Engineering tool
■Confirmation using the indicator LED
When C24 detects an error, including a reception error, the ERR LED turns ON.
■Confirmation using Engineering tool
Monitor the 'data transmission result' (Un\G599/615) to check the error code.
When a transmission error occurs, the CPU module may not transmit all the designated data.
Establishing any communication procedure by the user so that normal transmission can be checked by
receiving a response to data transmission is recommended.
3 DATA COMMUNICATION USING NONPROCEDURAL PROTOCOL
84
3.2 Transmitting Data to Target Device
Reference
Page 233 Send Monitoring Time (timer 2) Setting
Page 78 Send area and send data arrangement