Comms Monitoring of SCADA

[pcmccartney1 141]

Forum Members,

Time for a silly question.

I have an L33ER based system that is talking to a PC SCADA software called Ignition by Inductive Automation.  Not really asking about Ignition, but rather how to monitor in the PLC whether or not the communications is working properly. For a majority of Rockwell's products (on E/IP) you would simply add the module and generally there is a tag in the AOP or do a GSV on the Module.  Since this is a PC based SCADA, I'm a little lost trying to figure out how to monitor communications and availability.

Is the solution to create a Generic EtherNet Module, but I really don't think there is configurable instances or sizes of instances.

Ideas on what I should be thinking about or looking for?

 

Thanks,

Rick

[Michael Lloyd 85]

There are lot of ways to do this. We use a "heartbeat" script in the SCADA software for the PLC side of things. Basically it turns a bit on every time it's run. We run it every 30 to 45s. We shut our remote stations down if comm fails for longer than 600s. For the HMI side we use the Comm fail detection parameters that are built into the driver. In our case we use Kepware for most comm services. There is a health status bit (don't think that's what they call it but I can't check the HMI right now)

PLC logic looks like this:

 

[pcmccartney1 141]

Thanks Michael,

I've done "heartbeat many times, just had mental block on how to achieve this in a SCADA.  I guess the answer is a macro or script that writes to a tag that is exposed to the PLC.

Told you it was a silly question.

Edited 1 Sep 2017 by pcmccartney1

[Michael Lloyd 85]

Nope, not silly at all.

There is literally a tag called Heartbeat in the PLC and the script turns it on (and then "lets go so it's not latched in the HMI software). I read the elapsed time and some other stuff but the time value can't be read if there is no comm. Our graphics turn "magenta" if the comm status from the driver is bad. I'm kind of handicapped right now. I left my laptop in New Mexico when I came home to gather up the family because of the storm. Otherwise I'd be able to tell you what the value is in Kepware. Somewhere in the driver there is a tag for stale comm.