1756DHRIO Problem "Not a Logix Controller"

I am having a problem using a 1756DHRIO module to achieve remote access to a 1756-L55. We have a system with several PLC5s on a DH+ network. There is a KF2 module used to dial in to the network. A Controllogix system was recently added. I can dial in and go online with all of the PLC5s. The Controllogix shows up in RSLinks, correctly identified. In RSLogix 5000, I can browse to the 1756-L55, and the "Go Online" option is enabled. However, when I attempt to go online, after a short delay, I get the error "Failed to Go Online, the attached module is not a Logix Controller".

I am running RS Linx Classic v. 2.54

While on site I have used an ethernet module in the logix chassis to connect to all the PLCs, via the DH+ network.

After consulting with AB, the fixes I have tried were to remove the 1756DHRIO from the PLC configuration. I deleted the Harmony file. I have tried to go online in both run and program modes.

I would be grateful for any other ideas.

Thanks,
Ken F

hard to say without SEEING your setup - but are you "drilling down" through the DHRIO module - through the chassis backplane - then to the controller that you want? ...

tip: trying clicking the PLUS SIGNS in RSLinx to open each step of the path ... we usually call that "drilling down" ...

if that doesn't work, try posting a screen shot of the problem area ... we're not sure what you're doing from the description that you've posted ...

PS Edit :

another tip: try SHUTTING DOWN both RSLinx and also RSLogix5000 - then start them back up and try to go online again ... sometimes the software gets "hung in a loop" after an error ...

I am not sure if this will make a difference but check that you have the latest EDS files installed for the DHRIO. If the DHRIO module is Rev E, you may have to update.

Checked the EDS files

I did check the EDS files. The EDS for the 1756DHRIO is rev. E. I can browse online through RSLinx to the 1756DHRIO and check the configuration. The card is also Rev. E.

I also checked the EDS for the 1756-L55, both the EDS file and the actual processor are Rev. A.

I also have Rev. A - D EDS files for the 1756DHRIO installed.

Thanks for the suggestions.

Ken F.