Problem:
Reason is submitted from HMI but interlock is still on
Reasons: There are two reasons,
A) PLC is disconnected.
B) Value of ‘Reason submitted HMI’ variable is not written on ‘Reason submitted PLC’ variable(Variable mapping)
Issue analysis: There are two steps to check the issue,
Step 1- If the issue is still there-
Ping the IP of PLC on cmd prompt
ping <IP address> -t
Example - ping 192.168.1.170 -t and press the enter button.
If there is an issue with IP pinging then contact the Site support network engineer.
Step 2- If the issue has come and gone.
Check the historical data of the below variables when the issue came up,
A) Reason submitted HMI
B) Reason submitted PLC
Value of both variables are same then escalate this issue to Implementation Engineer
Note:- If the value of ‘Reason submitted PLC’ is blank in historical data it means that HMI was off or out of the network during this period.