Response Monitoring Time (Timer 1) Setting; C24 Operation By Response Monitoring Time (Timer 1) - Mitsubishi Electric MELSEC iQ-R Series User Manual

10.2

Response Monitoring Time (timer 1) Setting

The response monitoring time (timer 1) is a monitoring time for clearing the receive wait state of the device that receives a
response message when any trouble occurs on the side of device which received a message and the response message
(result) cannot be returned to the target device.
When C24 receives a message from the target device, it monitors the CPU module processing time up to the start of
transmission of the response message to the target device.
When a message was transmitted, it monitors the target device processing time up to the start of reception of the response
message from the target device.
The following describes the response monitoring time (timer 1) operation.
Message
Target device
CPU module
If on-demand data is transmitted before a response message during data communications using the MC protocol, the time up
to the start of transmission of the on-demand data is monitored.
Target device Command message
CPU module

C24 operation by response monitoring time (timer 1)

When response monitoring time (timer 1) is set to 0 ms
• After receiving a message, C24 does not monitor the time up to the start of transmission of the response message to the
target device, but waits infinitely.
• After transmitting a message, C24 does not monitor the time up to the start of reception of the response message from the
target device, but waits infinitely.
When response monitoring time (timer 1) is set to 100 ms or longer
• After receiving a message, C24 monitors the time up to the start of transmission of the response message to the target
device and returns the elapsed time to 0 at the start of transmission.
• After transmitting a message, C24 monitors the time up to the start of reception of the response message from the target
device and returns the elapsed time to 0 at the start of reception.
At time-out, C24 performs the following processing.
■Data communications using the MC protocol
• C24 stores the error code to the 'MC protocol send error code' (Un\G602/618) for the target interface.
• C24 transmits a response message (NAK message) to the target device and waits to receive the next command message.
■Data communications using the bidirectional protocol
• C24 stores the error code to the 'Data transmission result' (Un\G599/615) for the target interface and completes the
transmission processing abnormally.
• While waiting to transmit a response message, C24 does not check the response monitoring time.
Response
Message
message
Monitoring time
Elapsed time reset
On-demand data Response message
Monitoring time
Elapsed time reset
10 CHANGING DATA COMMUNICATION MONITORING TIME
Response
message
Monitoring time
Elapsed time reset
10.2 Response Monitoring Time (timer 1) Setting
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