adamaj (Customer) asked a question.
PLC-001 Communication Timeout, Event Display Screen
I'm attempting to have an ERROR screen display whenever communication times out. I created an Event in the Event Database for the error screen to display upon activation of the internal tag SYS_ERR_ERRORSTATUS.
If I disconnect the HMI from the network, the error screen displays, but then goes off after 5 seconds. The normal display is then visible for ~35 seconds, until the error screen is displayed again.
The only thing I can think is that the error state is not held while the EA9 is retrying communications? 35 seconds seems like a long time for that though.
Ethernet Settings:
Retries: 3
Timeout: 1 (100ms)
Poll Time: 0
You can change the alarm display time in the panel manager. By default it is set to 5 seconds.
What determines the rate at which the re-alarm occurs? As outlined in my original post, I’d see 5 seconds of alarm, 35 seconds of no alarm (though it was still timed out). What factors are determining that 40 second interval?
Also, somewhat unrelated. There is a grey bar at the bottom of the screen that says 01/01. How can I remove that.
Thanks,
Adam
PLC-001 is a system error for PLC comm. Nothing you created.
01/01 at the bottom is the error you created in event manager.
Hey Durallymax,
01/01 appears at the bottom of the screen when no error is present (default screen is displayed).
Does that display just because there is something in the Event Manager Database?
That bar will appear anytime an event is true(if you add a name to the event it will display with it). The internal system error bit you used for your event is true when there is no communication.
I finally tested changing the alarm time to 60 seconds, but this did not seem to help my original problem.
It seems like the System Alarm is clearing temporarily, even though communication has not been restored. The HMI goes into a strange state where the following occurs (between the 5 second alarm screen displays).
As stated in the original post, this occurs for ~35 seconds between the 5 second alarm display.
Frankly, I'm pretty surprised there isn't a straight-forward way to display an error screen if you lose connection with the target PLC. Seems like a state that you'd definitely want to be able to handle.
What you're experiencing sounds like correct behavior. I'm not sure I'm not sure I'm clear on what it is you are trying to accomplish.
None of the HMI buttons related to the PLC will function when there is no com with PLC. System buttons will function.
If you just want an error screen to pop-up when communication is lost, created an error screen and have that event trigger a screen change.
That is exactly what I want, and I want the "error screen" to stay up the entire time that communication is down. However, it doesn't do that. It flashes ON for 5 seconds and OFF for 35 seconds, and repeats that cycle the entire time that comms are down.
Not sure how that is correct behavior. Shouldn't it be in alarm state the whole time?
Comm Loss:
I see what you're saying. What you need is two events.
Use sys error status to set a tag to on in one event.
Use another event to trigger a screen change based on the tag that you set on. Then have a way to reset that tag as desired either through a button on screen if operator needs to ack or via another tag. I'm not sure off hand what sys tags are all available to make this work but it wouldn't be hard in the PLC either.
I found the problem causing the 01/01 to display. On one of the events that modifies the screen (sets it back to the default screen after comm alarm recovery), the "alarm" option was checked. Removing that check removed the 01/01 bar at the bottom of the screen.