Need devicenet backup crash course

chadc281

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Jul 2013
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Alabama
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A couple months ago we had a little siemens I/O module go out and in the process of replacing it with one with a different rev level it ended up costing 6 hrs of downtime. What became apparent about the whole situation was that we didn't have EDS files for some of the devices and generally we didn't have the proper knowledge to fix it fast. The devicenet config file we were using wasn't showing everything properly, probably our fault. so, I've been studying devicenet and rsnetworx for devicenet and at this point I really need some simple been there done that this is how you do it kind of advice. Primarily I need to know what I need to do to get current backups of all of our dnet's so that if we did have to replace a module or a scanner that we would have good data to correct the issue. We have a mix of compact logix and SLC 5/05's. I can't seem to connect to the dnet network through the SLC's Ethernet port. On the compact logix, I don't have any trouble getting down to the port 2 on the scanner and uploading from the scanner but I've got a lot of unknown devices popping up and I don't know if i'm supposed to upload from them or if i'm suppose to get the eds files for it first. Another thing I don't know if how to handle the EDS files for the devices and if I could change something accidentally messing with the EDS files. Mainly, I need to ensure that I know what i'm doing so that nothing changes. Could yall help me with this?
 
Well, like most Original Posters, you will need to add much more information.
My experience with these devices (a few thousand nodes) is that its all about the firmware, and, every detail counts.
But, lets not get ahead of ourselves.
FIRST you need a network riser diagram.
That would show the master, and all the slaves, with, at a minimum, all the part numbers, and all the hardware and firmware revision numbers.
Only when you have assembled this information are you ready to start worrying about RSNetworks for Devicenet (which has revision levels, of course), RSLinx, and the various .eds files.
...
Or, you could keep going the way you've started, and just run circles.
 
well, we definitely don't want to run around in circles which is why i'm seeking some knowledge.

The network diagram is one thing that we have started doing, but due to the amount of dnet devices we have, we were hoping that the details on the devices could be attained in a more automated fashion using software. So far all we've gotten is the I/O mapping per node number from the scanners. So are you saying that we can't use software like rsnetworx to develop a network map with all the details we need?
 
It's good that you're getting on top of it now. RSNetworx for DeviceNet is definitely the tool you want to use.

RSNetworx is very much a user-driven bit of software; you need to tell it each action you want to perform. Watch the status window carefully; it will tell you each time something is complete or if it's stopped or failed for some reason.

RSNetworx uses the same terminology as RSLogix: a download writes data from the RSNetworx project to a device, and an upload reads data from the device into the RSNetworx project.

The first step is to be able to 'get online' and browse the network. This is a lot easier with ControlLogix and CompactLogix, but as you've seen with older PLC-5 and SLC-500 controllers it's harder.

There is a '1747-SDNPT' passthrough driver that you might be able to use with the SLC. I think RA might have not updated it for 64-bit operating systems, though, so there may be some hoops to jump through. Do you have any other way to connect to the network, like a 1770-KFD or a 1784-U2DN ?
 
When I connect up with an unknown network to document it, the first step is to get the DeviceNet driver working correctly. If there's a device that will tell me the data rate (like an AC drive with a HIM module) I can be sure about the 125/250/500 kb/s rate, and I usually set my interface (often a 1770-KFD) to Node 62.

Next I open an empty RSNetworx project and browse the network. This is where a physical network diagram helps, because I can't be absolutely certain that all the devices that are connected are showing up in the browse. Sometimes I compare the scanlist to the browsed network configuration.

If some devices show up as Unknown, I go get the EDS files for them. AC drives I usually upload from (A-B drives are good at this), other A-B devices I get from the Rockwell EDS server. If you happen to be online with the network and an Internet connection at the same time, often RSNetworx can do this automatically when you ask it to download the EDS from the Internet.

Once I have the EDS files registered and everything browsing smoothly, it's time to do an Upload. Remember that just because you've browsed the network and see the device icons doesn't mean that you have any of the device configurations uploaded !

I either start with the Scanner then upload from each device individually, or use the 'Upload from Network' feature, which goes around to every device in the project and uploads from it automatically. Watch the status window carefully to be sure that every device really did upload.

NEVER use the 'download to network' function unless you are absolutely certain that the offline file has all of the configurations you want to load into the devices.

A good way to document a network is to use the RSNetworx reporting feature to create an HTML file showing all the parameters from each device. This can't be turned back into an RSNetworx project file (*.DNT), but it is an easy-to-read, easy-to-save way to see all the parameters in a device.

A parameter list is also handy when you get a new device with a different major firmware revision that RSNetworx can't make match up with the old configuration file. If you have what's essentially a text copy of the parameter settings, you have a very good chance to set up the new device correctly.

There are some decent 'how to do X procedure' PPS files in the RSNetworx program directory. I don't know if there's an easy way to launch those from the program, or if you just have to go digging.
 
Excellent information, I appreciate it. We'll be working on physically mapping out all of our dnet networks to ensure it's matching up to what renetworx is seeing. Now this may sound stupid but could someone explain to me the EDS files please. I'm confused as to what their purpose is. Is it just something my laptop needs to allow the software to communicate with the device or is it something that the device needs, etc. What if I installed the wrong EDS file on my laptop, could it change the way the physical device works? Also, along those same lines, is there anything I could do wrong (other than downloading) that could screw up the network, scanner or devices?
 
There is a '1747-SDNPT' passthrough driver that you might be able to use with the SLC. I think RA might have not updated it for 64-bit operating systems, though, so there may be some hoops to jump through. Do you have any other way to connect to the network, like a 1770-KFD or a 1784-U2DN ?

You know, I tried to install that driver while I was connected to one of the SLC's and it would flash up the little green check mark like it installed it successfully but it never showed up in my drivers list to where I could look at it or configure it. not sure what I did wrong there. I'm not familiar with the 1770-KFD or the 1784-U2DN, I would imagine that we do have one of the 1770's somewhere because on many of the networks, I kept seeing that device pop up after browsing.
 
So are you saying that we can't use software like rsnetworx to develop a network map with all the details we need?

Not at all. In fact, that will be one of the next steps.
All I am saying is that the hardware network riser diagram IS needed NOW. Oh, you can wait, and draw it up as you go along (as, I'm sure, some of the under-40 crowd will quickly suggest), but, experience says that very quickly you will be faced with a question like you've already mentioned...a node number pops up that is not expected. Hmmmm... Is it on the drawing? (hard to answer, if there's no drawing now, isn't it?). So, one of your first observations could easily be answered by a diagram. What? OEM didn't supply one? Oh, well, the system is not the OEM's anymore...get on with a diagram ===perhaps in parallel with the uploading of "what's in the scanner". [Keep in mind, the 'last guy' might have cut a lot of corners in the scanner configuration]
 
Not at all. In fact, that will be one of the next steps. All I am saying is that the hardware network riser diagram IS needed NOW.

Yea, I was hoping there was a quick and easy way of doing it but I can definitely see the need in mapping it out thoroughly the first time like yall have suggested. Some of it has been mapped by integrators already but most of it hasn't.
 
You know.....of the 1770's somewhere because on many of the networks, I kept seeing that device pop up after browsing.

I've browsed unknown DNets in the past, and seen echos of old programming devices...somehow the scanner knew about them, but, since they don't have process data (I/O) they don't show up as failed nodes. Weird, but, you're not alone in seeing one on a browsed network.
 
Yea, we've gone through several model changes over the last 10 years and all of those nodes are still there and still in the scanlists. This is one thing that I would like to cleanup as well since it makes troubleshooting difficult when the scanner's are all showing 78's on a bunch of nodes. However, on the nodes that I know are in place, like my Festo CPX I/O and valve packs, they show up with their correct name when it browsed the network. But, down at the bottom, it said something about changing it to a different applet and that since the configuration couldn't be maintained it would be reset to default values, something like that. That freaked me out so I was afraid to go any further and upload from them. I just backed up and punted, figured i'd study up on how to do it correctly.
 
It's common to see network access devices like the 1770-KFD or 1784-U2DN in existing RSNetworx for DeviceNet project files, because they were once part of the project file when somebody was using them. There's no harm in deleting them if you aren't using them (or are using one at a different address). They aren't part of a scanlist.

The messages in the status window are super-important. It's good that you paid attention to the 'configuration could not be maintained' message.

Let's say that RSNetworx finds a CPX valve bank on the network. There's also a CPX valve bank in the RSNetworx project file, but RSNetworx somehow can't migrate the old device definition into a new device definition.

Because it can't resolve the differences between the device on the network and the device in the project, it gives you that 'configuration could not be maintained' message. The icon appears in the project, but the parameters stored in the project are the default parameters that RSNetworx obtains from the EDS file.

If you were to perform an Upload, the parameters from the device on the network would be read by RSNetworx and placed into the RSNetworx project file object for that device.

If you were to perform a Download, the default parameters from the EDS file would be written into the device on the network. That would be bad, so don't do it.
 
I have no idea why that icon appeared above my post. My dog did have access to the keyboard for a while. She's a lousy typist and understands only the basics of DeviceNet.

The usual reason that you see that 'configuration could not be maintained' message is when the offline file and the actual device are of different Major Revisions of firmware, or are otherwise different (like offline is a 10A drive, and online is a 15A drive).

This usually happens when the offline file is from years before, and the network has been physically modified by substitution of devices, or when you've replaced a failed device with a new one that has different firmware.

In some circumstances, the RSNetworx 'applet' has changed in between revisions of RSNetworx software, so the new version of RSNetworx can't use the data saved in the old file. That comes up in situations where the network hasn't been changed in years. FLEX I/O is notorious for this.

But the solution is the same: Upload from the device, so that the RSNetworx project file has the current data values from the device itself.
 
But the solution is the same: Upload from the device, so that the RSNetworx project file has the current data values from the device itself.

Ok good deal. So, if it has recognized all of the devices on the network, there's none left off and there's no unknown's and i'm doing uploading only, no downloading, is there anyway that I could screw up an existing and functioning network?
 
The most common serious mistakes I see are:

1. Plug a device that's hard-set for the wrong baud rate into the network. This can (but won't necessarily) cause a Bus-Off fault for the scanner. A power cycle always brings the network back to operation, but there's some excitement for a while.

Autobaud works well on the devices that support it, and prevents this sort of issue.

2. Get too enthusiastic with clicking and select Download instead of Upload. You just have to be careful.

3. Accidentally short wires while working with open-style connectors. It's easy to forget that the red wire is +24V DC.
 

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