Troubleshooting finding what's affecting tag

Ignition
,
1

I recently took over a project for a coworker and noticed that we are getting an error from one of there loggers. This error is to warn that the Boolean tag was not turned off correctly. After the logger happens, it then flips the boolean tag itself. (Here is the script, but I don't think this is the problem:)

"""
	DESCRIPTION: Tag Event changes for matrox.status
"""

from time import sleep

logger = system.util.getLogger("SmartInterface_Rev2")


def dataReady(tagPath, currentValue):
	""""
		DESCRIPTION: Data Ready tag path change 
		PARAMETERS: tagPath (REQ, str): tagPath from change event
		RETURNS: None
	"""	
	logger.debug("tagPath: %s" %tagPath)
	RETRY_ATTEMPTS = 10
	
	if currentValue.value:	
		for attempt in range(RETRY_ATTEMPTS):	
			sleep(1)
			
			# recheck that the data ready has gone False
			dataReady = system.tag.readBlocking([tagPath])[0].value
			
			if not dataReady:
				break
				
			elif dataReady and attempt == RETRY_ATTEMPTS - 1:
				logger.warn("%s timed out, reset" %tagPath)	
				system.tag.writeBlocking(["%s" %tagPath], [0])

I started checking the PLC and found the tag is being latched within the code, but not being unlatched. I am having trouble finding where/what it is supposed to be unlatching this tag. I have even done some extensive searches within the find/replace tool.

We have 2 machines running off this program, one is working fine the other is throwing this error.

Is there a way that I can trend a tag so that I can find exactly what is unlatching the tag for the working machine and what is supposed to be unlatching the tag for the broken machine?

2

Depending on what version of Ignition you are using you could use the tag reference tracker to see where that tag is being referenced at and it's usage (write or subscription). Then utilize the last referenced and updates columns to see if you can tell what is unlatching the tag and then you will have a good place to start looking for what is supposed to be unlatching it.

Although I don't think it will show what is unlatching it if it is being unlatched by a script. So that may not do what you are needing.

3

You could setup an audit profile to identify who is writing to the tag.

4

I ended up using the tag diagnostics and found out that one of the transaction groups that used this tag, did not have the "Reset trigger after execution" checked... Thanks for the help!