Hello,
I have an HMI running an Intouch 9.5 application. It is communicating with a compact logix PLC via an external I/O server. The Intouch application is reading the PLC seconds clock (OIT_Handshake_TimeOut)from the I/O server and then via a "while showing" window script (a header window that is always showing)performs the following; OIT_Handshake_TimeOut = OIT_Handshake_TimeIn;
The PLC logic compares the two tags looking for a value difference of 3 seconds or greater for a period of 10 seconds to latch the heartbeat alarm bit.
The symptom is an intermittent (several times per week)heartbeat alarm. Interestingly enough, I do not get I/O server status alarms. Looking at my trended tags, the "OIT_Handshake_TimeOut" value from PLC looks normal (counting up) but my "OIT_Handshake_TimeIn" value that is written back intermittently freezes randomly for various time periods. It stops incrementing from less than a minute to several hours with about 4 or 5 minutes being the average. I have never seen a windows script used in this fashion and was looking for any feedback as to why I might see this "stalling" in the
"OIT_Handshake_TimeIn" value. Thank you very much.
I have an HMI running an Intouch 9.5 application. It is communicating with a compact logix PLC via an external I/O server. The Intouch application is reading the PLC seconds clock (OIT_Handshake_TimeOut)from the I/O server and then via a "while showing" window script (a header window that is always showing)performs the following; OIT_Handshake_TimeOut = OIT_Handshake_TimeIn;
The PLC logic compares the two tags looking for a value difference of 3 seconds or greater for a period of 10 seconds to latch the heartbeat alarm bit.
The symptom is an intermittent (several times per week)heartbeat alarm. Interestingly enough, I do not get I/O server status alarms. Looking at my trended tags, the "OIT_Handshake_TimeOut" value from PLC looks normal (counting up) but my "OIT_Handshake_TimeIn" value that is written back intermittently freezes randomly for various time periods. It stops incrementing from less than a minute to several hours with about 4 or 5 minutes being the average. I have never seen a windows script used in this fashion and was looking for any feedback as to why I might see this "stalling" in the
"OIT_Handshake_TimeIn" value. Thank you very much.