ABB IRC5 robot controller - Profibus problem.

Hey guys,

I am having some trouble with one of our profibus node on the network. We have an S7317 PLC (DP MASTER) with 5 Siemens slaves and 2 ABB IRC5 robot controllers.

**This is an intermittent problem

Only one robot is loosing communication with the master, and all other devices are still communicating. The robot is not the "end of line" and the slaves daisy-chainned after it are still working fine after the problems occurs. To get these info, I do a network diagnosis in the PLC with FC125-DPDIA.

Action I've already did:
We tried to re-install the profibus card - No change.
We tried to redo the connectors - wont do anything.
We tried to swap the DP Adapter from one robot to another - Problem is still on the same robot.
We finally tried to change all the cables - problem occured again.

Currently, I am solving the problem by simply rebooting the robot controller. Then it starts working for an undefined period of time. We have several other robots, all linked to a S7317 via profibus, and they are all working fine.

I think that I may have to change that robot controller, but im looking for a more "easy" way of doing this.

Any thoughts ?
Thanks a lot,
Jonathan Fournier.

Hi Jonathan,

The ABB IRC5 has as far as I know two possible DP slaves.

One is the earlier type which is a CAN-bus to Profibus DP converter (same one as used in the SC4+). You can check this by following your Profibus cable, if it does not end up directly in the robot PC-rack then that's the one. If this is the case you might want to to check the CAN-bus side of this converter. This converter gets its DP settings from the robot controller so if something goes wrong in the transmission between the converter and the robot controller it might interfere with the Profibus side too. I know that in the machines we build these converters get their powersupply (24VDC) from the PLC side, so not internally from the ABB controller.

The other is the converter directly in the Robot PC rack, in this case there is no CAN bus side to be checked.

For both situations there are some things you might want to check:

Check the earthing/grounding of the whole system, I know that we hook up massive ground lines through our whole machines, to both cabinets (including robot controllers) and mechanics (including the bases of the robot arms). Sufficient grounding connection between the PLC and robot controller are essential.

Check the firmware version of your robot (ABB calls it ROBOTWARE) and check with ABB whether there is a newer version. When this Profibus problem occurs, can you still operate the Robot? I mean can you jog or run through jobs? Can you still weld or operate a gripper? You can check the robotware version when you make a back-up and read the backinfo.txt in the BACKINFO folder.

I know there are more ways to reboot the ABB controller, not just the power up/down cycle. You can also reboot the controller from the teachpendant in several ways, each with a more or less deeper reset. Check with your robot guys about these possibilities.

If you let me know which DP converter,type of robot and version of ROBOTWARE you have I'll check with our robotguys if they can come up with some ideas.

Greetings, Gup

Hey Gup, Thanks for the reply!

Actually, im one of the robot guys. Im an hybrid doing PLC and HMI stuff too...

The robot OS (Ronot ware) is 5.10.03. Its the earliest version of OS availible for IRC5.

When the problem happens, Im still able to jog the robot, get the program cycling, but no communication with the PLC occurs. All our tooling are controlled directly by the PLC, so opening grippers, welding and stuff wont happen.

Concerning the rebooting of the controller, Im not cycling power directly. Im doing a "Warm start" on the teach pendant. I also tried a "P-Start", not working either. I migth try to re-install the OS this week. Hope this will solve the problem.

Now for the grounding. I'll have to check that up. This robot is an "Extra" on this project, and was installed after the first 9 ones. They may have screw the ground up.

The type of adapter we have is a card with a serial female connector on one side (To plus the ProfiBus connector). This card is plug in a slot on the robot CPU rack, rigth next to the DeviceNet cables going out to the drives. There is LEDs on this card, and they all stop flashing when I loose the communication between the robot and PLC.

I will take a closer look at the ground tomowow at our client's plant, and get the "real name" of this DP adapter card. I'll keep you posted.

Thanks, this migth help a lot!

Ok, i checked a couple of things..

Grounds are all good.
Name of the adapter is : ProfiBus DP-V1
I compared the card settings to our other robots, all the same.

Let me know if something comes up!
Thanks, Jonathan Fournier.

Hi Jonathan,

I've discussed this problem with one of the robot-guys here. There are no things we can think of with the information we have so far. I've send you a private message with an e-mail address. If you want you can send a backup of the robot and logfiles. My colleague has promised to have a look at it.

Greetings, Gup

Finally solved the problem.

An ABB guy came in to replace the robot mother board. Surprisingly, this did not fixed the problem. So we checked each connector on the network to find out that one had an intermitent ground.

No problem since then!