I have a tag "Pressure" im logging every second through the historian properties to a microsoft SQL database. I need to pull the value of that tag from X minutes ago in order to calculate the difference between X minutes ago and the value now.
The plan was to have seperate tags that would show this info easily.
i was trying to use querytaghistory() but im getting an out of bounds error.. is there any easier way to do this?
Is what i have scripted wrong
endTime = system.date.now()
value = system.tag.readBlocking('[default]Test Information/test parameters/Hold Period.value')[0].value
startTime = system.date.addMinutes(endTime, -value)
dataSet = system.tag.queryTagHistory(paths=('[default]Test/Pressure'), startDate=startTime, endDate=endTime,returnSize=1)
Are the history properties set up correctly also?