SSD 590+ DC drives and DeviceNet

Yes. We are currently testing DeviceNet Techboxes Version 3.4, and after 24 hours haven't seen any of the loss of communications faults that we saw with earlier revisions.

This seems to be an SSD Problem.

We have had these running for almost a year without any problems and within the last month we are having problems with all the SSD drive on this particular line freezing up.

The symptom we had, was one or more drives would just drop off of DNet for a period of time. In a 24 hour day, each drive would drop out several dozen times, for less than a second.

Occasionally, a drive would drop out for 5 to 10 seconds. This became noticable. Once in a while, more than one drive would drop off for an extended period. When they both tried to come up again (on DNet), all of DNet locked up, and required a powerdown cycle to get things running again.

If you are monitoring the actual DNet comms status to each drive, I'd bet you would be seeing lots and lots of short duration dropouts.

If indeed it is another problem (what is the scanner status during a drop?) you should probably check all of your connections and terminators.

Also, make sure the 24VDC DNet supply is in good shape.

I have run 590+ and 690's over DNet and had no problems at all.

I am with the SSD tech team in the UK next week so could ask if they have any known problems...

tactnuke said:

We have had these running for almost a year without any problems and within the last month we are having problems with all the SSD drive on this particular line freezing up.

Click to expand...

If its been running for a year then id look at wiring between units, has anything else chenged ? ie someones played with the configs ? another part of the machine has been modified/worked on? perhaps causing damaged to a dnet cable ?

You say the drives are freezing up, do you mean they are staying at their last valid dnet signals ?

What is the techbox light saying ? Tag 509 (from memory) gives the dnet connection status from the Drives MMI.

Have you got the drives configured (config ed lite - SSD Drive software) to detect a dnet comms fault and act accordingly ?

edit: Also does one drive "freeze" / fall over or is it all drives on the dnet cable ? Reason i ask is i had a problem at a site a while ago where the plc had been programmed to latch the dnet scanners bit ON on a first pass, occasionaly this somehow went back to OFF with no ways of turning it on again, solution was to take the first pass logic out and have the bit ON all the time. have you checked this bit when the drives freeze?

Its O : dNET_SCANNER_SLOT/0

If you havent already got/looked at the tech box manual heres the troubleshooting and diagnostics pages

Tag 508 in the drives MMi is Device Status (Output 1 in CED Lite)

Tag 509 in the drives MMi is Connex Status (Output2 in CED Lite)

Engineering went thru all of that and everything looked fine to them. SSD believes that our tech boxes are failing. We are running both Control Technique drives and SSD on the DNet and only having problems with the SSD's. So we are going to change the boxes at their recommendation and see what happens from there.