AB DeviceNet communicate with GE LM10

[tj5nguyen 0]

I am trying to connect to GE motor protection device LM10 through DeviceNet network using AB 1756-DNB. I could not get it to work. This is my first time of using DeviceNet. Please help!!!

[Ken Roach 194]

Could you add maybe some facts about what you mean by "couldn't get it to work ?" 1756-DNB configuration using RSNetworx for DeviceNet is really very simple. You add a slave device (the LM10) to it's scanlist, configure the data size and connection type, then tell the 1756-DNB where to put that data in it's I/O memory. Do you at least have the 24 VDC and termination resistors hooked up to your DeviceNet segment ? There is a nice tutorial that ships with RSNetworx for DeviceNet that describes configuring scanlists and using the various upload/download functions of the software. Can you tell us more about what isn't working on your system ? Any flashing lights, error codes, or other evidence would be really helpful.

[tj5nguyen 0]

Ken, All the network LED lights are showing OK status. The scanner is in run mode (commandregister.run is on). I try to use I/O polling with 7 bytes inputs and 1 byte output. By forcing a output (according to the I/O mapping) I expected to see a relay output on the LM10 to close and an input bit to become a "1". I did not get any close output and there is not any input bit changed to a "1". That is what I mean "could not get it to work" There is only one error that I got is the communication error when I tried to download to the LM10. But GE support specialist said that I cannot change any of the setup of the LM10 through DeviceNet and that is why it showed the error. However, all the lights are solid green. I just want to make sure I have the scanner working OK and it is not a AB problem Thanks Thi Nguyen

[Ken Roach 194]

If you have configured the I/O connection to be active and all the LEDs on the 1756-DNB are green, then there's nothing wrong with the DeviceNet configuration or connection. I am not familiar with this GE device; I sell and support their competition. Does GE publish an EDS file for this unit ? I was able to find a product website but all it offered was the NetVista software for configuration. I realize that your GE support person said you couldn't use the DeviceNet port to perform configuration, but I'd like to see the EDS file just the same. You could also ZIP and post your RSNetworx for DeviceNet *.DNT file to be absolutely sure it's correct.

[TimWilborne 108]

I am not familiar with this particular device but have had to deal with GE and Devicenet before. I would suggest you start with the basics. Since you mention Inputs does it have indicators on the module to show that they are high? If it does, put a jumper wire on it and make sure that the wiring is correct. Then go to you DNB inputs in the tag browser and see if it switched. This will let you know if you have any communications. Even none conformance tested products usually will have some type of EDS file. Like Ken said it would be nice to view this. We may be able to use it to monitor something of the unit under device parameters and we should be able to setup the class instance editor to read from the device. Just a few other basics, is the scan counter incrementing and are you able to turn on and off other devices outputs on the network. And for a real basic question, you say you forced an output bit, but did you have forces enabled?

[Ken Roach 194]

Found the EDS file for this device: http://www.geindustrial.com/cwc/products?p...d=lm10&typeId=9

[tj5nguyen 0]

Thanks very much for all the responses. I finally got the controls (start, stop, reset, etc...) to work. I obviously did not know much about DeviceNet. I was able to find some examples from an AB manual and finally make some progress. I am working on explicit messaging to get other information from the LM10. I donot think I have the right communication path (please see attached screen.doc file). I used the Browse button and that was what I get. I currently have 2 LM10 units on the network with addresses 2 and 4. What should I have for my communication path? Thi Nguyen screen.doc

[TimWilborne 108]

If DNB_00 is your devicenet module then your path to node 4 would be "DNB_00,2,4" DNB_00 tells it to go to your devicenet module 2 tells it to go to the first outgoing port(for the most part). 1 would be the backplane and 2 usually is a second port 4 is your node number Can you explain to use what was wrong with the communications for future reference?

[tj5nguyen 0]

There was something to do with GE EDS file. It did not let me upload or download to the device. The error look like this: "Address 04 communication error (0xC) 'Error response received: [0x0414, 0x00ff], Attribute not supported.', SCIA(0xE, 0x3, 0x1, 0x64), Param1" After I talked to GE support, he editted the EDS file and sent it to me. I used the editted EDS file and have no error message. Thanks

[Ken Roach 194]

It has TWO parameters and the first one doesn't match the actual object in the device ? Was it a different firmware revision, or just an incorrect EDS ? :rolleyes: I'll have a peek at the user manual and see if there's anything in the device's parameter group that aren't in the EDS. Can you post the edited EDS so we can compare it to the original ?

[tj5nguyen 0]

I think the new EDS file do not let the PLC look at the device's parameters (Parameter tab is not shown). But what do I know? so please see the attached EDS file. LM10_test.zip Here is the EDS file

[Ken Roach 194]

Yes, the GE technician removed the parameter section. He even noted it in the revision section: $ 01/20/06 Sanjay D For test removed parameters

[Ken Roach 194]

In the Parameter section of the original EDS, the "object path" for Parameter 1 and Parameter 2 is exactly the same. 6,"20 03 24 01 30 64", We can parse that out; it means that the parameter is Class 03 Instance 01 Attribute 0x64 (100 decimal). Unfortunately, that can't be right. Class 3 is the "DeviceNet Object", which according to the User Manual, only defines Attribute 2 (data rate) and Attribute 5 (Master/Slave Connection Allocation Information). Attribute 100 isn't mentioned. The Parameters descriptions tell us that Parameter 1 is supposed to be "Full Load Amperes", with a value between 5 and 8100, with a default value of 270, all of which are divided by 10. Parameter 2 is supposed to be a Fault code between 0 and 2. When we go to read the User Manual, we do find an FLA parameter as Class 0x2C, Instance 0x01, Attribute 0x03. There's also two FLA settings in the "Overload Object", which are Class 0x64, Instance 0x01, Attribute 0x02 and 0x03. Those sound closer to the original path, so maybe they just got the path definition backwards. You can proceed to fiddle with the LM10 via explicit messaging as defined in the User Manual. GE Industrial should have provided a complete and correct EDS file for this device.

[tj5nguyen 0]

Ken, I was able to read and set the parameters one at the time. Is there any way that I can set a group of parrameters at the same time? Thi