AB Servo DeviceNet with 1747-SDN

[psychosunshine]

I have a 1398-DDM-009X-DN that was talking to a 1747-SDN in a rack with a SLC 5/05.



Recently, after a download of new parameters to the servo drive. It stopped communicating with the PLC.


The inputs and outputs to and from this servo drive do not appear to be working. All the other devices on the DeviceNet network are working.


The number on the 1747-SDN display is 00 and both LEDs are green. With no errors.


The BCD switches for node address and baud rate, have not changed on the servo drive and are set to the proper settings.



What do I need to do, so the 1747-SDN can see this servo drive?


I tried to connect to the module with RS Networx through the Ethernet port on the 5/05 CPU, with no success.


If I need to use RSNetworx, how do I connect to the network or the 1747-SDN module?

 

[tom_stalcup]

Does that servo drive have an option to enable/disable the communications?

I don't know if this applies to that model drive or not, but I have seen similar problems with a different series drive.

The Ultra3000 drives that we use on a fiber optic network have a setting in the drive to enable/disable the sercos (fiber optic) option to use the drive as a standalone drive. However, to change that option requires using the ultraware software package to plug directly into the drive.

 

[plvlce]

I have a 1398-DDM-009X-DN that was talking to a 1747-SDN in a rack with a SLC 5/05.



Recently, after a download of new parameters to the servo drive. It stopped communicating with the PLC.


The inputs and outputs to and from this servo drive do not appear to be working. All the other devices on the DeviceNet network are working.


The number on the 1747-SDN display is 00 and both LEDs are green. With no errors.

Unless the drive was removed from the 1747-SDN scanlist, the fact that you see no errors on it indicates that the scanner does see the drive.

You should be able to verify this by unplugging the DeviceNet connector from just the drive -- the 1747-SDN should then show a fault for the node # that the drive is set to. If it does not, then it seems likely you have somehow dropped the drive from the 1747-SDN scanlist.

I tried to connect to the module with RS Networx through the Ethernet port on the 5/05 CPU, with no success.


If I need to use RSNetworx, how do I connect to the network or the 1747-SDN module?

Ideally for upload/download of parameters you should use a 1784-U2DN usb to DeviceNet adapter.

If you configure the SLC for pass-through (see the 1747-SDN manual) then you can browse through the ethernet port if you set things up correctly. This is intended for fine-tuning and adjustment of network devices, the connection is not suitable for complete configuration or real-time monitoring.

 

[psychosunshine]

Thanks. That is very helpful information. I will check this evening if when I disconnect the drive, if the SDN module faults.

 

[psychosunshine]

OK. Before I unplug the Servo drive from the DeviceNet network. Already, I have an error blinking on my 17476-SDN module. It's blinking 78, 17, 80, 00. So, I know that my node 17 is not communicating.

So, when I disconnect the servo drive, Node 18, the error does not change.

Do you think that the servo drive is no longer in the scan list?

 

[plvlce]

Error 80 indicates that the scanner is in Idle mode -- make sure that the PLC is in Run and (if error persists) that the Enable Run bit for the SDN module is set.


The error 78 for node 17 indicates that scanlist has a device with that node configured, but does not see it actually present.



The fact that your drive, configured for node 18, does not produce an error 78 when disconnected suggests that the scanlist does not have a node 18 configured.


In other words, the scanner is looking for a node 17, but you're only providing a node 18. How confident are you that your drive supposed to be node 18, not node 17?



I'm not familiar with the drive family you are using, but how is your node # set? If it's set as part of the parameters (updating which caused the problem initially) is there any chance whoever was updating them changed that parameter?

 

[psychosunshine]

OK. I did get an error 78 for Node 18. I did not notice it. Because, it was on a different 1747-SDN module. This rack has 2 1747-SDN modules. So, Node 18 is in the scan list for the other 1747-SDN module. When I plug it back in to the DeviceNet. The fault goes away and the module is happy. Although, when I send it commands. It does not seem to respond.

 

[plvlce]

Okay, so the node 17 error is a red herring, not even being on the same network.



At this point we can say that there is not a physical issue, and the communication settings in the drive, although not necessarily correct, match what the scanner expects to see. This makes it unlikely that the issue is with the scanner.


From here you should take a look at the (new) parameters downloaded and make sure they are correct; ideally with a copy of the previously working parameters for comparison.


As mentioned, I'm not familiar with this drive series, but looking through the manual I would suggest paying close attention to parameter #283 (DNET I/O Format), #287 (Logic Cmd Mask), and #289 (Enable behavior).

 

[psychosunshine]

OK. So, this is an Ultra Series servo drive. I use UltraMaster software (V1.60) to access the drive parameters.



I do not see any parameters for DeviceNet in the software.



Are you talking about parameters viewable in RSNetworx?