One-Shot Button Fails to Load on Startup

Ignition
1

I have a one-shot button that’s used in a very typical way: write a value to a tag (happens to be an OPC tag, in this case), and wait for the tag to be cleared before writing another value. I’m having an issue, however, where the button will say that it’s writing, as though it’s been pressed, when first viewing the page it’s on after starting a client, but the tag is cleared and ready so the button should not be in that state. Navigating away from the page and back to it clears the issue, but that’s not an acceptable solution long term. I’m guessing this might have to do with erroneously reading a bad value at startup, as I’ve seen similar issues to that issue before.

Edit: clarification

2

Refreshing this issue because I still haven’t found a solution. Anyone out there seen this?

3

Never seen this before. Are you sure you don’t have some script writing to the button’s control value on window load?

4

Yes, I don’t have any scripts that run when loading this window.

5

What version of Ignition are you using?

I’ve seen issues with unwanted writing to tags in Ignition 7.9.7 and above. In my case, it happened on a popup that had two or more bindings of different instances of the same UDT type.

Would it be possible to create a minimal example (create a copy of your window and remove as much as possible while the problem keeps existing), and share that here?

6

I’m running 7.9.5 at the moment. There isn’t really much to share, it’s just a one-shot button that writes a value to an OPC tag, then a PLC on the other end of the OPC connection writes a 0 to reset the one-shot. The value that get’s written is property-bound to a drop down menu of options.

7

Put a delay in the PLC between seeing the nonzero value and clearing it back to zero.

8

Yeah, so there already is because the PLC has actions it takes before it will write it back to zero, but that has nothing to do with the problem. The problem is that only on the first time the page is loaded after a client is started, the button appears as though the value has not been cleared even though it has. No action should have been taken, as the button hasn’t been pressed, so it doesn’t have anything to do with when the PLC has cleared the value.

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