SMB Error etc

duesentrieb66

Hello all,

the robot is a IRB6640 235 255 04

We get all weird error messages from SMB, over Axis, Encoder fault etc. Most of them is SMB. We replaced already the board in the controller and robot with no luck. ABB told us it is most likely the SMB cable but the weird thing is that we get the error when the robot is in waiting position and NOT in movement. Anyway, we ordered a new cable just to be sure.

Also there are days with no errors at all and then the whole day nothing then trouble. The robot has around 8000 hours.

I must say that the controller was sitting under a roof, outside for a winter with minus temperatures of -15 degrees celcius. my gut feeling tells me this was to much...

Anyone has any idea what it could be?

Thanks!

xerim

Have you tried replacing the battery? 

duesentrieb66

Yes, just replaced. In the ribot and track. 2 weeks old.

Also replaced smb module in robot and conteoller.

duesentrieb66

The most error we get is the SMB error. Here the log:

SMB Communication Failure                   2002-06-06 23:39:18     A transmission failure has been detected between the axis computer and the serial measurement board on measurement link 1 in Drive Module 1.

Sounds like the axis computer?

xerim

Have you ruled out the cable being faulty? I would try that next. Also, after you calibrate the robot when it loses connection with the SMB, how long until the error appears again? Immediately or after some time?

duesentrieb66

the error sometimes comes instantly or not for days. The error can go away after a reboot or stays all day. The error mostly comes when the robot stands. more and more also during movements. we can not find any pattern at all.  other that it gets worst lately. I also pinged the cable 1:1 and could not find any problem. Not sure if I checked for a short but we defiantly get signals for 1:1 wires.

we ordered the cable but we are weeks away and need to produce now, so i don't know if it is the cable.

My plan would be to cut the smb cable a foot after the connector on both sides and replace it temporary with multiple cat-5 network cables. Not pretty but we could move on. What do you think?

xerim

Do you have an oscilloscope? I would double check you are getting a signal at both Serial Data out (SDO) and Serial Data In (SDI). Another signal to check would be the exciter signal going to the resolvers. Use the oscilloscope to check the amplitude of the signal, or to see if there is any noise on the line. 

lemster68

What does the robot do?  Spotwelding maybe?

duesentrieb66

milling

no electric fields nowhere

duesentrieb66

Thanks for all your help.

It was the cable.

I bypassed all the ABB stuff from the controller to the robot with a rs232 cable and 2 sub9 connectors and all was working. This confirmed I ordered the original SMB cable (1500$?!?) and we're back in production.