I am having trouble creating an expression tag. I have a pump that I need to look at a few tags that if it faults it will blink red. How do I write my expression tag so that if any one of the tags become true it will fault my pump. I know how to make the pump flash red but i just don’t know how to make this pump look at several tags at once. Thanks.
In the expression tag:
{path/tag1} ||
{path/tag2} ||
{path/tagN}
If any of your tags become true, this will turn your expression tag on.
I’m looking at bits of a memory word from a plc for these tags, does my data type need to be boolean or something else? Thanks
Are the memory words a collection of status bits or a status int?
For what I posted above, {path/tag} don’t need to be boolean as long as the OK (pump not faulted) state is 0. When the value of that tag (boolean or integer) goes to anything non-zero the expression will return True and, in your example, the pump would fault.
Hope these pictures actually went through, this is what im working with. Is there something i’m doing wrong here? We just switched to ignition last year and we are trying to work out all the bugs with it, we don’t have much experience with it yet. Thanks
What version of Ignitio is this?
7.9
Nvm. Didn’t look at all the pictures. Sorry.
What type of tag are VFD Fault, Comm Fail, and Fail to Start?
Edit: They look like maybe UDTs, but I’m not that familiar with 7.9.
It’s okay our tech support guy is out right now, so i thought id look for answers and help on here
tagBool
They don’t show values in the tag browser, which is why I asked if they were UDTs.
Yes they are UDT’s
In your expression you need to provide a path to a thing that has a value (probably one level deeper). Your UDTs don’t inherently have a value associated. I can’t take a screen shot on 7.9, but there is a button in the top right when you’re writing your expression that looks like a tag. That will let you pick tags from a gui instead of typing them out.
Yes thats where I got my tags from, I didn’t type them I selected them from the insert tag button on the top right.
@zacht is just saying you need to expand the UDT, there should be a tag inside of it that is probably an int or bool that gives the status for that alarm condition. You need to use that, the UDT itself has no value associated with it, it is unaware of the tags inside of it. If you hit the plus next to the 3 tags you want to monitor what does it give you inside of the UDTs?
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Okay, may be getting somewhere now. I can now see a 1 for the value of that expression tag because for this particular pump i do have an alarm active. But when I assign the expression to the pump the pump doesnt like it for some reason.
If your binding it to an object on the screen and there is an issue, it should give you some kind of error. I’d look in your console in the designer to see what the error states. It may also give you a popup for the error depending on what it is.
Okay I got that worked out, thought I wouldn’t have issues with this ethier but is there something i can add to this expression so that when any of those are true to make the pump flash red? Thanks