Eric Nelson
Lifetime Supporting Member + Moderator
For those familiar with the E-terminals, I have a question about the alarm acknowledge (ACK) function. Here's the scenario:
In the PLC, I have individual bits that get SET when a fault occurs. One specific bit for each fault. When the ACK button is pressed, I use the "Acknowledge Notify" to RESET that specific alarm bit in the PLC. This works fine the majority of the time, as there's usually only one alarm bit ON at any given time. Since that alarm is the only one active, pressing ACK resets the bit and the alarm is cancelled (and acknowledged in the HMI).
The problem happens when more than one alarm is active. Pressing ACK only resets the most recent alarm. The only way to reset additional alarms is to go to the alarm history page, then individually highlight and ACK the other unacknowledged alarms. This is too confusing for the operators.
What I'd rather do is have the ACK button trigger one bit in the PLC to reset ALL active alarms. This is how I normally do it with other HMIs. The problem is that I can't assign the ACK button to trigger a bit in the PLC. Sure, I could just assign one of the other buttons as an alarm reset, but I'd rather use the ACK button.
I've tried changing all the "Acknowledge Notify" bits to use only one specific bit (instead of the bit related to the alarm). I then use that to reset ALL alarms in the PLC. This DOES reset the alarm bits in the PLC, but it doesn't show up as 'acknowledged' in the HMI. I can't uncheck "Acknowledge Required", because then I don't get the ability to trigger a bit in the PLC...
Anyone know of a possible 'workaround' to this?...
beerchug
-Eric
In the PLC, I have individual bits that get SET when a fault occurs. One specific bit for each fault. When the ACK button is pressed, I use the "Acknowledge Notify" to RESET that specific alarm bit in the PLC. This works fine the majority of the time, as there's usually only one alarm bit ON at any given time. Since that alarm is the only one active, pressing ACK resets the bit and the alarm is cancelled (and acknowledged in the HMI).
The problem happens when more than one alarm is active. Pressing ACK only resets the most recent alarm. The only way to reset additional alarms is to go to the alarm history page, then individually highlight and ACK the other unacknowledged alarms. This is too confusing for the operators.
What I'd rather do is have the ACK button trigger one bit in the PLC to reset ALL active alarms. This is how I normally do it with other HMIs. The problem is that I can't assign the ACK button to trigger a bit in the PLC. Sure, I could just assign one of the other buttons as an alarm reset, but I'd rather use the ACK button.
I've tried changing all the "Acknowledge Notify" bits to use only one specific bit (instead of the bit related to the alarm). I then use that to reset ALL alarms in the PLC. This DOES reset the alarm bits in the PLC, but it doesn't show up as 'acknowledged' in the HMI. I can't uncheck "Acknowledge Required", because then I don't get the ability to trigger a bit in the PLC...
Anyone know of a possible 'workaround' to this?...
beerchug
-Eric