Powerflex 700 Comm Failure

I have an Allen Bradley Powerflex 700 VFD and I have replaced the 20-COMM-D Series B Communications Card 3 times and changed out the entire VFD with a new one and then swapped it out with the 3 different Comm Cards. It says Port 5 Adapter Error after 3 seconds of starting the VFD up. It is node 10 on my Devicenet network and in RSNetworx it has a Red icon with a yellow (-) sign indicating it is in the configuration but Not on the network. I have also replaced the Devicenet cable. The option to download to device is grayed out.

Is the error code on the drive 75, or 85 ?

75 means the problem is on the DeviceNet.
85 means the problem is on the DPI network between the 20-COMM-D and the PowerFlex drive.

Is this an intermittent problem that finally became acute, or a one-time thing that has not happened before ? Are there any other functioning devices on the network ?

DeviceNet is not hard to troubleshoot, but like any other technology you need to examine the indicators closely and take notes.

Error code 75

There are approximately 25 other functioning devices on the network including another VFD that exactly matches this one.

Hey, great !

Now, what's the error code on the DeviceNet Scanner ? Is it the same error code that led you to exchange the drive and the three 20-COMM-D modules ?

This might be a simple configuration problem, or there might be something damaged in your wiring.

Just started producing this fault yesterday afternoon.

I'm leaning towards a simple configuration problem but I don't see how I can troubleshoot this without the node being available for configuration. It has the option to "Re-Register" Device and asks for an EDS file to use but the EDS file in my files to use doesn't match or doesn't agree with the device it says in a prompt that pops up during the test.

The PLC scanner modules have a little display on the front that shows an error code alternating with the DeviceNet node address of the offending device.

Post those numbers here.

It would also be handy to know the part number of the PLC scanner.

The 20-COMM-D module also has some rotary switches for the address and data rate, and some LEDs that give you status information.

Have a look at those and post information about their state and color (on, off, flashing).

All the LEDs on the COMM-D are lit Green and the node address rotary setting is set to "1" and "0" for node 10 and 500K Baud which matches the rest of the devices on the network. I'm not quite sure what you mean by Devicenet "Scanner" I have a Controlnet to Devicenet converter module here but it doesn't have a display, I do have a red led for a module fault though. It is a "Linking Device 1788-CN2DN A" Devicenet cable coming in the front and Controlnet leaving out the bottom.

You're going to have to get online with the ControlLogix and look at the Status tags for the 1788-CN2DN.

The 1788-CN2DN has the same sort of diagnostic information as the 1756-DNB, but it's only in the Status tags and obviously there's no scrolling display.

There's a SINT[64] array for in the Status connection, and you'll find a value in element [10] for the device at Node 10.

Edit: the tag name should be something like BridgeModule:S.DeviceStatus[10]

You're looking for a 72 or 77 or 78 error code (or something else). That error code will tell us what to do next.

It would be best to know what the original error code was from yesterday afternoon, as now we don't have the same drive or 20-COMM-D so we have to deal with firmware and EDS file issues in the software, rather than just solving the original problem.

But the method is still the same: get the error code, and go from there.

Ok I had to do some digging and figuring out but I think I found what you are referring to. I went to I/O Configuration on the ControlLogix tree and found the Device Link. Right Clicked, selected cross reference and then Tag tab. Found The Status Array and then element 10's status bits. Device Status [10] has a 16#4D Hex value in it which 4D is 77 in Decimal. Every other Device Status is 00. I hope thats what you are looking for.

I still have the old VFD and Comm Card and can hook them back up if need be to avoid an EDS file problem. I also have the second VFD which can be copied or carried over somehow. During my time looking up the Status Info my co-worker found that the new VFD was set for Port 0 not Port 5. Switched it to port 5 but still have the comm fault.

Error 77 is a "I/O Connection Size Mismatch".

It's a configuration error cause by the 20-COMM-D's parameters for "Data Links" being configured incorrectly.

It is almost certainly NOT the same problem that caused you to change out the 20-COMM-D modules and the drive, because it cannot just occur randomly; somebody would have had to reconfigure the 20-COMM-D to cause it.

In the offline RSNetworx project, look at the parameter values for Parameters 13, 25, and 26. Those will tell you what the settings were in the original drive (hopefully).

You can use the HIM module for the drive to set up those parameters in the 20-COMM-D.

Those parameters are described in the 20-COMM-D User Manual.

You can also check the size of the I/O connection for this drive by examining the Scanlist for the 1788-CN2DN, or by checking the other drives if you think they are similar.

Those parameters are stored in the 20-COMM-D itself, so if you plug it back in you shouldn't get Error 77 anymore.

Final solution, Parameter 14 needed set to (00011) and also Parameter 26 needed set to (00011). Once this was set RSNetworx itself promted there was an identity mismatch and asked to correct the situation and when it did we were back online and running right. Thank you very much for all your help.

That was short lived... Back to Fault: Port 5 DPI Loss