Alarm on SCADA

[Mushu 0]

Hi, I would like to know how could I detect on my SCADA that an Allen Bradlley SLC5/05 stopped. at the moment i am using S:1/13, but I would need to shutdown (go to the sequence number 0) my system when this bit is on. the problem is that when the bit is on: PLC is stopped, and one the bit is reset, my system does not go to cero, because the bit is false. thanks, Mushu

[Guest Guest_silva.foxx]

Is your SCADA looking for S:1/13 after the reset? How is our SCADA looking at S:1/13? Is it tagged? Is your S:1/13 setting a latch? If so, is it resettable?

[Ken Moore 23]

You could monitor bits S:1/0-S:1/4 to check that the processor is in remote run mode. Here's a clip from the SLC reference manual.

[Ken Moore 23]

Perhaps a better solution would be to write an initialization subroutine, so that everytime the processor starts, it resets to a known safe condition.

[mlarkinp 0]

Write a routine that toggles a bit in the PLC at 1 sec(Any interval that can be seen will do) intervals. You can use a small indicator on your HMI to show the bit flashing. If it is not flashing, then the processor isn't running. It is the simplest way I know of. Sort of like a heartbeat for the PLC.

[Guest Guest_Mushu]

thank you, I think the start up subroutine and the heartbit will solve my problem thanks again