devicenet driver questions

Hi guys, been awhile. I currently have a problem getting online to a devicenet network that we have. The machine is run by a PLC5, and has various AB160 drives taht are run with devicenet communication modules. While I can open up the devicenet program with my laptop, I cannot go online. Previously there was a KFD driver set up on this laptop, I am assuming to talk to this network. After doing some research I decided to try using the 1771 sdnpt-1, because we are using a 1771 sdn scanner. After setting up the configuration, in RSwho it shows the driver running but it finds nothing. However, when I look under driver diagnostics and events, it shows that it tried to go online, and then says that it is online with the network and functioning properly. I will keep toying with this, but if anyone has any input it will be appreciated. Also, feel free to ask questions if you need more info, as I know I have not been real specific. Thanks in advance.

russ

update

Ok, I have given up for now on the 1771 dns driver. I deleted it, and went back to the KFD driver. Since then I have installed the driver in Linx, and hooked up serially. I can see the devices on the network when looking in RSWho in Linx. When I upload the devices from the network, all goes well. However, when I try to start the diagnostics scan, I get the message that no devices on my network were found, browse the network and check for them there. I browse the network, and I see nothing. Can anyone tell my why I see the devices and can upload their parameters and such, but I cannot run a diagnostic scan? I do have the nodes I'm interested in activated on the scan, so I do know that it's not from having nothing activated. I'll keep dinking with it.

Russ

The 1771-SDNPT driver is *relatively* new.. you need 1771-SDN firmware version 4.1 or later to make it run.

Dunno why your diagnostic scan isn't working. You do have the M&D activation on this computer, right? It's separate from the ordinary RSNetworx for DeviceNet activation. You ought to see some kind of informational message in the message window if a software component fails.

I usually use the 1756-DNB bridging function to go online with the M&D survey. Hmmm. What version of RSNetworx do you have ?

another update

Ken,

Thanks for the reply. I will answer your question tomorrow as I am on my way out and I just read your reply. I am not sure what version of Networx I am using, but I will look and answer you tomorrow, as I said. I think the biggest share of my problems lies in my laptop, as I have had other problems with it as well, such as logging on to the company network for emails and the like. I did finally end up getting a diagnostic scan to run, but I am not sure whether it was technically running all the time. I activated the node I was interested in, and began monitoring it. After about 15 minutes the drive did fault again, and according to my diagnostic scan, everything was hunky dory with that node. Also confusing for me, I expected that if one of the 160 drives"(nodes) had a fault, that I should get a fault code on the DN scanner? Is this correct thinking? As it were, the status light remained green throughout the fault, and the status numbers remained at 00. I am definitely going to learn a lot tonite when I come back in, but all your input is definitely appreciated as well. Thanks.

Russ

Okay, if it's a drive that's having trouble you're going to have to take a step back.

It's entirely possible for a drive to "trip" in one of it's protective modes (overload, stall, ground fault, etc) without ever having anything go wrong on the network.

Have you retrieved the last four fault codes from the Bulletin 160 drive using RSNetworx (Parameters 7, 17,18,19 on my demo unit). Those might tell you if there's been a network problem or a drive problem.

If there is a network interruption but it's resolved in less than a second, I suppose it's possible for the 1771-SDN to never display it on the front panel display (it's "scrolling" information, after all).

You should be able to trap a brief connection fault by monitoring the Status block transfer. Check out the Installation Instructions manual for the 1771-SDN for a good reference about the I/O and Status block transfers available from this module.

http://www.ab.com/manuals/io/1771/1771-in014b-en-p.pdf

Thanks Ken

Ken,

I am sorry it has taken me so long to reply. I am having technical difficulties logging on to this site, and am working with Phil on this matter. I just wanted to give you an update. Per your suggestion, I have determined that the fault we were getting was an overvolt fault. I am not sure why this became a problem all of a sudden. The motor runs constantly on this particular machine, until a door is opened or another fault shuts the machine off. I checked the DC bus voltage as the manual says, and found it to be of normal value. I did do 2 things which seem to have helped. #1, I lengthened the decel time per the manuals recommendation, and also slowed the line speed down in motor rpms from 1575 to 1500. Since doing this, I have not had a single trip. It is my belief that when the drive clutch kicks in, it was causing some kind of ruckus which in turn was faulting the drive. I feel that simply slowing down the motor RPM had the greatest impact. I am wondering if anyone else has any experience or theory ideas as to exactly what was happening to cause the fault. The machine is running and everything is great, but the desire to understand exactly what was going on inside the drive will not let me sleep. Thanks again for the help and suggestions Ken. Greatly appreciated.

Russ