RSnetworx issues

fuzzydiode

Member
Join Date
Dec 2003
Posts
12
I am a beginner with RSnetworks but have managed to register various devices and config the scanner (using Micrologix 1500 PLC). The problem I am having is the RSnetworx seems to forget the EDS files if I restart the program. It says the devices are not on the network and if I re-register them it is OK until I restart RSnetworx again. The devices it forgets are non-AB parts and are still functioning on the network even though RSnetworxs can't seem to find them. I am not sure if I should just ignore this or what. The one thing I was thinking is I don't have full administrator rights and maybe RSnetworx cant save something.

Anybody ever seen anything like this?

RP
 
Let's expand on what you mean by "forgets".

Start with the offline *.DNT file. When you open it up with RSNetworx, are the "forgotten" devices still in the project ?

If they are still in the project, does the software give you a "this device is not registered" message ? If that is the case, then there is something wrong with the EDS registration process, which does write an entry to the Windows Registry.


Next let's address your statement that "It says the devices are not on the network". That message can show up in Online mode, when you browse the DeviceNet but the software cannot identify on the network the devices that are in the offline project file.

This can happen when the devices are actually disconnected from the network, or when there are noise or cabling problems on the network. It can also happen with some devices that can only maintain one "connection" at a time; you lose the ability to send them explicit messages (configuration and monitoring) once you start sending them I/O messages.

What precisely are the 3rd party devices you're using ?
 
I apologize if this is the second time I reply but I don't see my first response. Anyway I have problems with a Mitsubishi E520 drive and Matric Dual Inclinometer. First is they DNT file remembers the devices when I open DNetworx but ussually will have error 2014 and 021E which is "Our EDS services component did not register properly" and "The applet used to configure this device did not initialize properly. The devices and scanner seem to be working properly. I get data from the inclinometer and the LED on the drive seems happy. When running I get 0013 error sometimes "The device at address 01 has experienced an identity commumications error. Properties failed." This is the E520 drive. If I click on it it will usually verify the idenity and so I can see the parameters the second time I click. The first time the box doesn't show the parameters, I/O data ect. So I hit cancel and try again. Then the parameters come up and I can change them. Wait a while and I go through the same thing again. All though this I am not showing any comm errors on the scanner or drive.

RP
 
I think you are having two separate problems.

First, there is definitely someting wrong with the function of the EDS-based parameter editor applet in RSNetworx. You do need Administrator Rights to install RSNetworx, and I think also to register new EDS files. It might mean a tussle with your IT department, but you're going to need those rights.

The second problem of sometimes getting "identity errors" and sometimes being able to go online with the drive points either to some noise or traffic problem on the network, or a problem with the drive interface's ability to handle explicit messaging.

Is your Interscan Delay set for the default 10 milliseconds ? Do you have access to a 1784-PCD card (to run some DeviceNet traffic analysis) or a NetMeter or DeviceNet Detective to run some signal analysis ?
 
After playing with this thing most of the day, I agree that I probaby have several problems. I have had some preliminary discussions with a AB rep also. I think the first thing to do is go fight with the IT dept like you suggest.
Regarding setup, I am using a 1784-PCD card for the computer interface. Anyway the interscan delay is 10ms and the signal doesn't look to bad on my scope. I have a setup with all 1 meter AB DN cables coming off a Device port. The scanner is hooked to the connector on the end. I put 2 120 ohm resistors across the CAN lines. One is on the scanner and the other on the 1784 connector. I also grounded the shield and 24Vgnd to chassis like they recommend. Overall I have a very small network and if noise is still a problem I am not very impressed. I don't know about traffic analysis but on my scope when RSlogix and Linx is runnign I can see that it is about 10ms between bursts with about 1.4ms burst length. Sometimes there is a somewhat random burst in between. This is OK I think, however when I go online with RS logic it goes to about 100% (or more) activity. RSnetworx is not running at this point. I stay offline and go online with RSnetworx (still doesn't find devices) and have maybe alittle more activity then when RSlogix is offline, but going online with RSlogix is a mess. Also I am running at 125Khz. I used the serial port instead of the DN as the channel between the PLC and PC and the network traffic went back down.

I guess this is enough of my problems for now. I was trying to use CIP messaging also to read/write a parameter in the drives. Seems only succesful about 10% of the time without errors, but I imagine it is related to the other stuff.

Thanks
RP
 
Your network description is physically sound. Anytime there are AC drives or motion controllers I'm a stickler about grounding, and you would me amazed how many installers just throw the installation manual in the trash.

I think you may have a Mitsubishi problem. Mitsubishi has had erroneous EDS files on their website as recently as November 2003, and I had a counterpart spend three days at a pump station with his protocol analyzer before Mitsubishi sent him new firmware for their DeviceNet interface.

I'd like you to try one experiment. In RSNetworx, change the Interscan Delay from 10 milliseconds to 100 milliseconds, and change the Expected Packet Rate (under Module -> Advanced) to 1000 ms.

This may slow I/O traffic enough to allow the Mitsubishi drives to handle both explicit messages and I/O. Let us know the results.
 
Thanks, I will give it a try. I spent some more time talking to AB today and am trying to get ahold of someone from Mitsubishi that knows about DN and their drives. The guy at AB suggested trying about what you suggested. My computer is back in the IT dept, so they can try to figure out how to make the EDS registration problems go away without "violating corporate policy". Hopefully if I get it back tommorrow I can give it a try.

RP
 
Well I have my computer EDS file registering problems fixed and although RSnetworx still puts a - sign on the drive sometimes it always shows the parameters when I click it. I slowed down the scan rate as Ken suggested and I think that did the trick. A closer look at the Mitsubishi data says 30ms minimum. So I believe I have the network working.

My current problem is I cannot figure out how use the "msg" to make the drive do anything. I can successfully read a parameter but cannot seem to write one without getting a error. The Mitsubishi drive has assembly objects that should do most of the functionality I need. I have searched ABs site for some information on this regarding ML1500 but haven't found anything.

If anybody knows were any examples of this are I would greatly appreciate the info.

Thanks for your help
RP
 
Let's make our own examples !

Okay, you're clearly using a 1764-LRP controller, as that's the only MicroLogix 1500 that supports DeviceNet explicit messaging through the 1769-SDN scanner.

Explain what Service/Class/Instance/Attribute settings you are using in the working MSG that reads from the Mitsubishi drive, and in the non-working MSG that writes to the drive.

What is the error code you're getting when you send the Write message ?

If there is an online source for the Mitsubishi DeviceNet interface user manual, I'd like you to post that so I can have a look at how they implement their services.
 
You are correct on the PLC parts. I am also using a Mitsubishi FR-E520-0.75KND Inverter. I do not know where the datasheet is on the web. It was sent to me. I will send it to you or anybody else if you would like it.

To read a parameter I have used the MSG, with
Channel = Expansion Comms Port, Slot 1
Communication Command = CIP Generic
Data Table Address (Receive)= B3:4
Size in Bytes (Receive)= 2
Message Timeout = 50
Target Type = Network Device
Local Node Addr = 2
Service = Generic Get Attribute Single
Class (hex) = 28
Instance (hex) = 1
Attribute (hex) = 7

To attempt to write

Channel = Expansion Comms Port, Slot 1
Communication Command = CIP Generic
(Send)= N7:4
(Send) = 2
Message Timeout = 255
Target Type = Network Device
Local Node Addr = 2
Service = Generic Set Attribute Single
Class (hex) = 28
Instance (hex) = 1
Attribute (hex) = 7

I get error e0. I have tried to attach of gif of the MSG setup box.
I have also tried to use class 0x04 assembly objects. The documentaion states the default is Class 0x04 - Output instance 21 and Class 0x04 input instance 71. The way I understand this is I should be able to change and read the "parameters" by moving words to the correct mapped location on the 1769 scanner. Again it seems that I can read but cannot change anything.

RP

message2.gif
 
That should be fairly straightforward: Class 0x28 (Motor Data), Instance 1 (this motor), Attribute 7 (rated voltage) is said to be a Get/Set object by the Mitsubishi documentation.

Try running this same message with the SCIA Editor (right-click on the object in RSNetworx).

It's possible that RSLogix 500 is misrepresenting the error; it might be Error 0x0e (object not settable) instead of Error 0xe0 (an undocumented Class-specific error code).

Maybe the Mitsubishi drive won't allow you to set Motor Data once the drive is enabled, or once the DeviceNet I/O assembly is active. I know some objects inside A-B drives become non-settable once the drive is running.
 
Well I have managed to get the drive to turn on and off using a class 0x04 assembly object. The default assembly object for the Mitsu drive is Output instance 24 which has 4 bytes and includes fwd and rev and speed reference among several other bits. Input instance 71 reads back the about the same actual data. I simply move the data to the mapped polled I/O locations the scanner uses for the drive. So at this time I still can't get the msg function to write paramters but I can turn the drive on and off to whatever speed I pick and change directions.

What I would like to figure out is how to change the default Class 0x04 input and output instance(s). According to the manual the Output instance 126 (26 in the manual) and 176 (76 in the manual) use 6 data bytes instead of the default 4 and include parameter write and read capablity. This seems easier to me the the msg function.

Do you have to modify the EDS file to do this or am I missing something?

RP
 

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