Specifying The Cpu Response Monitoring Timer - Mitsubishi Electric QJ71MB91 User Manual

7
PARAMETER SETTING

7.3.6 Specifying the CPU response monitoring timer

When the QJ71MB91 receives a request message from the master and the programmable
controller CPU starts its processing, the QJ71MB91 waits for the response from the
programmable controller CPU. The time allowed for the QJ71MB91 to wait is set by the
CPU response monitoring timer value.
This timer allows the QJ71MB91 to cancel the wait status on the master side when a
response to the master is not available due to an error occurred in the programmable
controller CPU.
Master device
QJ71MB91
CPU response
monitoring timer
Programmable
controller CPU
(1) CPU response monitoring timer processing
(a) Start of the CPU response monitor timer
(b) If the CPU response monitoring timer has timed out.
1) 2)
Start Reset
Processing
Figure 7.12 CPU response monitoring timer operation
The QJ71MB91 starts the CPU response monitoring timer when it receives a
request message from the master. (1) in Figure)
The CPU response monitoring timer monitors the programmable controller CPU
processing until the QJ71MB91 starts sending a response message to the master.
(2) in Figure)
When the CPU response monitoring timer has timed out, the QJ71MB91 performs
the following processes. (In figure 3))
1) Issues error code: 7380
2) Issues the exception code: 04
7.3.6 Specifying the CPU response monitoring timer
Start
Error occurring
.( Section 11.4.3)
H
to the master side.(
H
7.3 MODBUS Device Assignment Parameter
3)
Timeout
Section 11.4.2)
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