OPC tags not working in designer

We have a server running version 7.9.0. any new opc tag I drag into designer does not work. what am I doing wrong. is there a limitation to the amount of tags on the server?

There is no limitation, other than computational demand and OPC driver’s load factor for the situation. What exactly is the problem?

it does not matter if I drag a Boolean or an int into the tag browser anything new will not work. all the old connection paths is still working. even if I copy paste a bit or integer already in the tag browser it will say null in the status column

I vaguely recall some OPC driver bugs from early v7.9 versions. Try disabling and re-enabling the OPC drivers involved, and if that doesn’t help, try disabling and re-enabled the OPC module itself. Or upgrade… (-:

why do these dates not match?

Get off 7.9.0. There are a laundry list of bugs, but one of the most significant was one that affected 7.9.0-7.9.3 and caused all scan class execution threads to get hung up in certain circumstances.

The reboot resolved the problems that the Ignition server was having regarding PLC tag communications and is acting normally again.

+1. Glad you got it going, but upgrading will help keep it from happening again. No cost for you to go to 7.9.9, hot off the presses.