Hi all,
We recently created a new connection to a PLC and after some networking issues, we were able to get the gateway to see the connection properly now. While we can see the tags being created and assign them, we only will get 'bad' readings out of the source, and trying to write to the tags gives an error 'Error Writing to Item'
"GatewayException: null
caused by QualityCodeException
Ignition v8.1.22 (b2022110109)
Java: Azul Systems, Inc. 11.0.16.1"
The gateway has many other tag sets that work just fine, and even another PLC that was added recently that worked fine. Read Only is set to false
We are using the same driver as the other sets and verified that with the PLC techs, Allen-Bradley Logix Driver. And the tags the techs set up are set to external read/write as well.
I have tried different processor slots on the connection path to see if it was something in there, as the processor is set on slot '0', trying 1 through 5 only made it where I could see a barebones PLC device folder, with just the diagnostics folder inside.
No logs have shown up in correlation with these sets either, so I'm not sure where to dig in, or if I just need to submit a ticket, and have IA look over my shoulder. Thanks for any suggestions.
What type of PLC, what firmware version, and what Driver are you using?
Is the PLC connected over Ethernet or some other means, are there any intermediary devices (routers, NAT's, etc...)
If this is a ControlLogix 7x or 8x, and you are connecting to the device via the controllers ethernet port, then you shouldn't have to set anything more than the IP Address in Ignition.
You might want to call into support and have them take a look, especially if this is urgent.
Networking
Gateway is set up as a VM going over ethernet to main routers to PLCs, and we do utilize the backplane connections where needed. This is one of them, so I have a VM going to a main router over ethernet,
then to a PLC over ethernet, then backplane hops to a localized router on a 192 address, with it ending on a 0 slot processor.
Can you browse the PLCs' web servers - both the good and the bad?
If there is a NAT router between the gateway and the PLC then have you configured the PLC's (network) gateway address correctly?
There isn’t really a choice here. For this processor as it is currently configured in order to set up a device connection in Ignition you must use the Legacy driver. The fact that you can not see the controller with it suggest that something external to ignition is hosing the communications.
Perhaps @Kevin.Herron can give some more insight into what the issue may be?
Well... there's not really enough information here for me to speculate, but you have it backwards. The "v21+" Logix Driver does work with old firmware versions, but with an extreme performance hit because all access is done symbolically instead of using the new instance ids introduced in v21.
It's the legacy driver that cannot read/write to v20.15? (.18? .19?) or later revisions.
All the A-B PLCs have a built-in web-server that allows some simple diagnostics and chassis browsing. Use your browser and enter the PLCs IP address (and optionally port :80) to connect. If this works then your routing is working.
Tip: use the Reply button if you want a user to receive an inbox notification of a reply. Alternately use the @username syntax in the post. I only found your reply because I revisited the thread.
I do not have access to browse PLCs like that. We have techs that do the in-house networking and ladder logic programming. I only touch the Ignition/database/reporting sides, so I just have to middle man some of these suggestions, and that may be why I'm unsure of what some of them are.
On top of that, I'm also relying on second-hand information as far as PLC types/firmware versions go. So I tried the suggestion of using legacy drivers for it, with no avail. That being said, we use (for the most part) the same PLCs with (again, mostly) the same firmware. That isn't to say the tech isn't mistaken about the PLC or its firmware, but it does seem like it should work with the current set up, so I feel like it is a PLC programming error or network configuration, not allowing the data to flow. Still working on it.
Sorry, I think I hit the main 'reply' instead of the post reply. I can try it, but I have to remote into a different computer, as we have 2 separate networks. I'll give it a shot.