AB 1756-ENBT/A Not Visible in RS Linx

Hi all,
I have been having trouble with a ControlLogix PLC containing a 1756-ENBT/A Ethernet card. The revision number of the card is 4.003 Build 2.

I have several ControlLogix PLCs with 1756-ENBT/A Ethernet cards installed, although this is the only one of this revision number (the others are older revision numbers).

According to some discussions I have had, there has not been a problem communicating with this PLC in the past, but since I started with my current company I have not been able to access this PLC via ethernet. I have no trouble accessing the other PLCs. Other expertise has all moved on, so I am it!

Up until yesterday the Ethernet card appeared in RSLinx with a question mark next to it. All other Ethernet cards were appearing correctly. In an attempt to get this card recognised, I loaded all the 1756-ENBT/A EDS drivers from the Rockwell website. This has now caused the problem Ethernet card to disappear completely within RSLinx (when running RSWho). All other cards are still present.

When I open RSLogix5000 I can see the Ethernet card but get a message "Failed to go online with the controller. RSLinx Doesn't recognize the communications path. Try checking the path by browsing it in RSWho". Once again, all other PLCs are fine.

Does anyone have any information they can provide regarding this problem? I have some issues in this part of my plant at the moment and really need access.

I am running RSLogix5000 15.02.00, and RSLinx V2.42.00 Build 18

Welcome to the Forum !

First, figure out the IP address of the module. That's easy because it scrolls across the front display.

Try using PING to be sure you can connect with the module from your computer.

If that succeeds, put the module's IP address into a Web browser. If you see the onboard diagnostic web pages, you know you're connecting to the module successfully.

Those two steps prove that you have a good configuration in your PC and that the network between you and the module is OK.

Then you're ready to troubleshoot RSLinx.

Are you using the "Ethernet Devices" driver, or the "EtherNet/IP" driver ?

Ethernet Devices requires you to enter the IP address of the module into a table in the RSLinx Classic configuration.

EtherNet/IP performs a network browse using broadcast packets. This sometimes fails when you're using a VPN or when you have more than one network port enabled (like when you have WiFi turned on).

I always fall back to the older Ethernet Devices driver when I'm troubleshooting, because of the simpler direct TCP connection.

You're right, by the way, about the yellow question mark meaning the EDS was not installed.

A yellow question mark with a red X means there's no communications at all to the module.

A yellow question mark without a red X means that RSLinx can communicate with the module but that it doesn't have a matching EDS registered.

Unfortunately I think your revision of RSLinx is old enough that it doesn't have the convenient "upload EDS from module" feature.

This is what I remember about EDS files, which if wrong someone will correct me.

Your Version of RSLogix 5000 is quite dated, and if your version of RSLinx is the same vintage, and your ENBT is newer, then RSLinx won't have the EDS file required' as it comes with the Linx disk and gets loaded to the RSCommon file once registered.

If you have loaded the latest EDS files for the ENBT from the Rockwell site, did you also register those files via the EDS wizard, as without that registering of the file it won't work for you.

edit
I see Ken Roach has come to your help whil I was tying
He is a resource I alway take notice of

And one really important note:

When you download the EDS file from RA, do not put it into the \RSCOMMON\EDS directory. Put it on the desktop or into some other download directory where you can find it.

If it's already in the \RSCOMMON\EDS directory when the Registration tool runs on it, much unhappiness will ensue.

Thanks for the quick response guys. As an update to what is happening:

I can ping the PLC without any trouble. I can visit the webpage with no issue. I have a Cimplicity SCADA system that is communicating without fail, and I have now found another PC in our office that also has RSLinx and RSLogix5000 installed. This PC has no trouble browsing the PLC and going online.

Interestingly, the only difference between my PC and the other PC is the version of RSLinx. The other PC has version 2.51 (I think off memory). The versions of RSLogix5000 are the same.

When installing the EDS files I used the tool to install them from the desktop, so I think I did this correctly. I am using the Ethernet devices driver and have found the Ethernet card in the table. I have tried removing and re-adding this.

I guess I am out of trouble in the short term as I can use the other PC to connect, but I would really like to repair the problem on my PC. Could it be the RSLinx version, and if so can I get away with updating to a newer version of RSLinx Lite? I currently have RSLinx Classic Pro (I think) and do not want to lose too much functionality.

The good news is that the main difference between RSLinx Lite and RSLinx Professional is the activation. I always just download Lite and install it, and my activations make it start up as Professional.

One thing you could try to do is clear out the driver configurations. You can back them up first (there's a menu option for backing up the RSLinx configuration into an RSX file) or just take notes.

Shut down RSLInx, then go into the \RSCommon directory and delete the Harmony.HRC and Harmony.RSH files. They will be re-created the next time you start RSLinx.

In RSLinx, try setting up the Ethernet driver instead of the Ethernet/IP driver.

Hi guys,
Thank you for your assistance. I have upgrade to a newer version of RSLinx that I found on one of our servers. After carrying this out the PLC is now visible in RSLinx and I can monitor it using RSLogix5000.

That's one to remember for the future.
Steve