Comunication between Staubli robots

[soiber2000]

Hello, I'm writing and application under val3 language to manage the movement of 2 staubli robots (tx). I have problems when there is a shared place where only one robot at a time can go there. The comunication between the robots is not correct when I use a sio variable (ethernet) with one server and one client. I tried to make a simple case where if robot1 needs to go at the shared place it sends a 1 to the other and when the other needs to go there it sends a 2, so when the server (robot1 in this case) knows the place is empty (the variable related to the sio is at 0) it "gives" the place resource to itself or to robot2, puting that sio variable to 1 or 2.

This method is not correct because when one robot reads what the other sends him, the comunication have some kind of delay that makes the robots don't work properly about 60% of the time.

If someone have experience in comunication between two staubli robots in val3 I would be pleased to read his comments and if there is a better way to do this I will thank to know that a lot.
Thanks

 

[tygerdawg]

If you have I/O points available, it seems it would be much simpler, easier to debug, and more robust to connect at least one pair of hardwired signals between the two bots. Set the signals based upon TCP coordinates in workspace. For failsafe, set signal high when NOT in shared space. Negotiate which bot goes first through clever programming.

TygerDawg

 

[yuki2]

Also, make sure you take into account race conditions.

Both robots could set and check the io at the same time and think that they had contol and then crash into each other.

I think you need more bits between the two machines.

 

[soiber2000]

Thanks to everyone, I've solved the problem, it was just a silly error in character they use to mark the end of the string in each communication.