ControlLogix DHRIO - DH+ Global Status Words?


Thread Starter

Trevor Ousey

Hi all,

We are currently installing a group of ControlLogix processors into lines
running DH+ with PLC5's and SLC's. And with these lines we have utilised
the use of the Global Status Words.

After some looking, I found technotes on getting the active nodes on a DH+
channel on the 1756-DHRIO modules, but have not been able to find anything
on the Global Status Words. I would believe it to be available with
generic CIP messaging. Any ideas would be appreciated, TIA.

Trevor Ousey
BJH Controls

Larry Lawver


Global Status Word support is NOT planned at this time for the DHRIO module. <Insert appropriate profanity here.> You may join the chorus for future relief by contacting your local RA area manager.

I need to work around this myself for a current 5/04 to CLX upgrade project involving nine CPUs, so I'm going to know what to do in about a month. If I get there first, I'll post my solution. I'm thinking of updating an array in one CPU and reading that back into all of the others. Meanwhile, if anyone else is ahead of the curve on this, please post your workaround!

Hope this helps!

Larry Lawver
Rexel / Central Florida
Anybody managed to solve this problem? Any recommendation?

Thank you in advance!

Best regards

James Ingraham

Sorry, Fernando

I'm afraid that there's no way to get Global Status Words into a ControlLogix. There are no good options. However, all is not lost. Presumably, the data the PLC/5 is putting in to a Global Status Word is also in a register somewhere, and you can do a MSG Read. It won't be as fast, it won't be as elegant, and it requires explicit MSG commands (potentially many of them), but it should work. If the data is NOT already in a register, you'll have to get in to the code and duplicate it to one (or many.)

-James Ingraham
Sage Automation, Inc.