CompactLogix DeviceNet configuration

[technolog]

We refurbish tube end formers and benders. I'm currently working on an Addison TEF. It has a 1769-L32E with a 1769-SDN DeviceNet scanner (see attached photo). I'm an absolute novice on DeviceNet.

There are two items (apart from the scanner) on the DeviceNet network - two Rexroth VT-HACD-1-10/V0/1-D-0 (R901040277). These are hydraulic motion controllers, one for each of two axes. Each HACD has a Balluff SSI magnetostrictive position transducer connected to it.

On axis 1, I'm seeing the feedback in the PLC, albeit not in the registers I was expecting, but that's easily fixable. I'm seeing no feedback from axis 2. When I swap the HACD cards over (so that axis 1 (DeviceNet address 1) HACD is connected to axis 2 feedback, I see the axis 2 feedback in the axis 1 PLC location, so I know the transducer and cabling are working.

I tried opening RSNetWorx for DeviceNet (know nothing about it!). With it connected online to the scanner, I see the two HACD cards (see attached DN1 screen capture). When I do a diagnostic scan, I get green check marks although after 82 normal "scans", I get two minor recoverable faults (see DN2) - I don't believe this is anything to worry about as the feedback on the working axis appears to work indefinitely.

When I look at the scanner device properties on the Scanlist tab, it seems to only show address 1 as being scanned (see DN3). The Input tab shows the feedback populating the registers that I'm seeing change in the PLC in response to transducer movement (see DN4). The Output tab is also populated with the position command from the PLC to the HACD motion controller. This looks to me like the crux of my problem - address 2 isn't in the scanlist. I poked around, trying to figure out a way to add it but cannot for the life of me figure out how to do it. Can anyone offer any insight into my problem and how to fix it, please?

While typing this post, it occurred to me that the transmit and receive buffers in the axis 2 HACD may not be set up, so I'll take a look at that.

 

[technolog]

To follow up, the DeviceNet configurations of the two HACD cards seem to be identical with the exception that one is address 1 and the other is address 2

 

[Ken Roach]

I used to start my classes by telling students "DeviceNet is like swimming: if you take it seriously and learn the basics it's a lot of fun. If you just jump in and start thrashing around you're going to have a bad time."

You've brought a fairly complicated multi-vendor application to the party, but it sounds like you're taking it seriously and not pushing buttons you don't understand. Don't hit Download or Auto-Map or Set Defaults !

One thing that's missing is that RSNetworx doesn't look like it has an Electronic Data Sheet registered for those motion controllers. That would help it understand any configurable registers/parameters/objects in the device.

Not having an EDS also means that the RSNetworx project surely doesn't include any configuration information on those modules. We need to be careful to make sure we upload and capture anything that's available.

Does the vendor provide an EDS file ?

 

[Ken Roach]

And I agree that the fundamental issue appears to be that only one of the motion controllers is in the 1769-SDN's Scanlist.

The Scanlist is really several different features: it defines the I/O connection type (poll/strobe/COS) and the I/O connection size, as well as the device identity keying that the Scanner goes through before starting the I/O connection.

It also defines where that I/O data goes in the 1769-SDN's I/O data table, both for Input ("Consumed") data from the slave devices, and for Output ("Produced") data sent to the slave devices.

Examine your CompactLogix program to see if there's similar code for DWords 0 and 1 as there is for DWords 2 and 3, and that might tell you where the program expects the other motion controller's data to get mapped.

 

[Ken Roach]

The "Invalid Slave" notation in the Scanlist just means that the RSNetworx project doesn't have an EDS file so it doesn't know anything about that slave device's identity. The data is probably being exchanged between the Scanner and Node 1 just fine; if you unplug the slave device you should see the status code 78, then 72, alternating with the Node 01 number.

 

[technolog]

The "Invalid Slave" notation in the Scanlist just means that the RSNetworx project doesn't have an EDS file so it doesn't know anything about that slave device's identity. The data is probably being exchanged between the Scanner and Node 1 just fine; if you unplug the slave device you should see the status code 78, then 72, alternating with the Node 01 number.

The HACDs plug into Eurocard-style holders with screw terminals so I can't unplug the DeviceNet but when I unscrew the two DeviceNet white wires from their terminal on axis 1 HACD, I get the code 91 on the scanner. Not sure if it's relevant, I suspect not.

 

[technolog]

Thank you for your generous input, Ken. It's the end of the day here but I'll be back on it tomorrow and would like to pick your brains a little more, if that's okay?

 

[Ken Roach]

The 2-digit display on the 1769-SDN isn't super verbose, but it's better than nothing.

DeviceNet node numbers are 0-63, so A-B decided to start error and status codes at 70.

Status code 91 = "Bus Off", indicating there is no usable differential signal on the CAN_H and CAN_L (white and blue) wires. That makes sense if you've removed the wires from the only other device on the network.

There was a CompactLogix plus 2x HACD threat a bunch of years ago on this forum... it would be wild if this was the same machine.

http://www.plctalk.com/qanda/showthread.php?t=34779

 

[technolog]

There was a CompactLogix plus 2x HACD threat a bunch of years ago on this forum... it would be wild if this was the same machine.

http://www.plctalk.com/qanda/showthread.php?t=34779

It's not the same machine Our scanner's in slot 3 so I'm reading and writing data to Local:3:I.Data[0] / Local:3:0.Data[0] not Local:5:0

So is the EDS vital or does it make DeviceNet config easier? I've searched for it on both the US and German sites but cannot find it. I've contacted our Rexroth distributor to see if the HACD tech support has it.

I have the Rexroth Start-up DeviceNet Interface manual (RE30143-03-z_2007-08) which says the following:

Start RSLinx and browse the bus with the interface being used. The VT-HACD will
have a default node ID of 63. After the browse is complete the screen should look
similar to the following.

<screen grab missing>

After this the user has to start RS Networx. Start a browse of the DeviceNet network
by going online. After the browse is complete RS Networx will display the DeviceNet
network with all the devices that were detected. The following screen illustrates this.

<screen grab missing>

After establishing that the VT-HACD is connected to the DeviceNet network and is
recognized by the software a Node Commission to the controller has to be performed.
In the menu bar of the “RS Net-worx for DeviceNet” screen under Tools “Node Commissioning”
may be performed if not previously done using BODAC. The program
prompts you to browse for the device that needs to be commissioned. After completion
the program will return with the following screen.

<screen grab missing>

The Address and Data rate shown in the above screen have to match
the setting of the DeviceNet Hardware screen.
To view the HACD controller parameters and read-only values over DeviceNet double
click the controller from the RSNetworx online screen and select the Parameters tab.
Now perform an upload. After the upload a list of all the items in the EDS file should
appear in the DeviceNet Parameter screen.

It sounds pretty straightforward but I'm fairly sure the Node Commissioning dialog was either unavailable to me or offered no apparent functionality. I'm wondering if the EDS file somehow opens up further functionality?

Anyway, I'm going to give it a go and see if I get any further.

 

[technolog]

It appears from my further investigations, that the EDS file is vital. I tried to upload from the DeviceNet network and got messages that nodes 1 & 2 were skipped because they're unregistered.

More worryingly, I noticed an error message associated with node 2 HACD that I've not noticed thus far. Are you able to shed any light on what the error means? See attached screen grab.

The Rexroth distributor has put me in touch with a guy from Bosch Rexroth, so I'm hopeful of having an EDS file in my sticky mitts soon.

 

[technolog]

I also looked at the setup of the data in both of the HACDs. The two nodes are identical apart from their addresses and node 1 seems to broadly agree with RSNetWorx' view of the data too (node 2 not visible yet), but I'm struggling to see why the input data starts in 1:I.Data[2] rather than [0] - any ideas? See screen grabs.

 

[Ken Roach]

Node Commissioning is just setting the DeviceNet Object settings: the Node ID address, the Data Rate (or Autobaud), and sometimes the bus-off reaction parameter. There used to be a standalone tool for that, but generally it's launched from within RSNetworx.

The EDS file gives RSNetworx information about a device, starting with the identity information and the default I/O connection parameters.

The most common other thing an EDS file can do is provide the low-level parameter object numbers, description text, data types, and scaling for device parameters that can be set of the network.

For a motor overload, that might be the FLA and the Overload Class. For a photoeye it might be the Light/Dark Operate or the Excess Gain limit.

I'm not sure what parameters the HACD exposes to DeviceNet and lets you adjust via RSNetworx.

To view the HACD controller parameters and read-only values over DeviceNet double click the controller from the RSNetworx online screen and select the Parameters tab. Now perform an upload. After the upload a list of all the items in the EDS file should appear in the DeviceNet Parameter screen.

 

[Ken Roach]

I'm not sure I can explain why the person who mapped that Scanlist put the Input data starting at [2] instead of [0], but put the Output data starting at [0].

Maybe they had another Input-only device, maybe they just made a mistake.

The obvious reason that the 1769-SDN isn't communicating with Node 2 is that Node 2 isn't in the Scanlist.

And you can't put something in the Scanlist if it doesn't have an EDS registered with the software so that the software has at least a tiny bit of information about its identity.

It's worth continuing to try to get that EDS. But you can also generate a "Stub EDS" that includes only the basic ID and manually-entered I/O connection information that's necessary for RSNetworx to make a Scanlist entry.

Having that HACD -> DeviceNet I/O image information will make understanding the underlying logic much easier.

 

[KuulKuum]

The Rexroth distributor has put me in touch with a guy from Bosch Rexroth, so I'm hopeful of having an EDS file in my sticky mitts soon.

So did you try the EDS file from the thread Ken linked earlier?
To me it has the same part number you mentioned.

https://www.plctalk.net/qanda//showthread.php?t=34779

 

[technolog]

So did you try the EDS file from the thread Ken linked earlier?
To me it has the same part number you mentioned.

https://www.plctalk.net/qanda//showthread.php?t=34779

Ha!

I'd seen it in the thread but sort of dismissed it as I didn't know it was for my exact model of HACD (there are quite a few - though only about 4 or 5 DeviceNet versions). However, I've just opened it in Notepad and, indeed, it's for my exact model of HACD! Thank you KuulKuum!