Fanuc Robot Stuck "Busy"

    Hello, I am having a strange issue on a R30iB Plus V9.4 Controller. The controller sporadically gets stuck busy and running, it seems to always be on a motion instruction, it gets to the line in the program and then freezes for an amount of time without moving and then suddenly springs to life.

    I can press HOLD, turn on the teach pendant, even E-Stop the system and the Run and Busy indicators stay illuminated for an amount of time. The teach pendant is not frozen, I can still navigate perfectly fine.

    I have seen the issue both on Roboguide and on the physical system but can't find a pattern of what is causing it or reliable recreate the issue. I have two Ethernet IP connections, a Profinet connection, Proface HMI connection via SNPX and a few BG Logic programs.

    Ethernet IP are both only 2 words IN/OUT, Profinet is 16 Words IN/OUT, SNPX Assignments are 10 string registers, details of 5 current alarms and 200 registers.

    Any ideas would be appreciated :smiling_face:

  • Nation December 15, 2024 at 6:23 PM

    Approved the thread.

    Is your Program setup in a loop that it always returns to that motion instruction at the top? (See my example below):

    I've seen code similar to this where, the If logic isn't satisfied, and the busy lamp acts as you're describing. Simple solution was to throw a small wait statement after LBL[1].

    I have BG Logic programs but no Karel programs and no simultaneous programs.

    I do have a main loop but there are no motion instructions in the loop itself, the loop checks load/unload conditions of different stations in the system then calls the required load/unload program.

    I don't know if this helps but as far as I can tell, the issue doesn't happen if the program has been stopped

    Update: It seems that adding the wait to the start of the loop has fixed the issue, I had previously tried adding a wait just before the motion instructions that it gets stuck on but that didn't help so I nearly dismissed your suggestion xD

    I guess the controller gets bogged down running though the main loop so quickly when all conditions are false.

    Thank you!

    Quote from HawkME

    There is really no reason to have a continuous running TP program on a robot. That isn't how they are intended to run and makes troubleshooting difficult. Use a wait instruction to wait on a start signal. The start signal can come from a PLC or the robots own BG Logic.

    Almost every main program on every robot I have written in the last 35 years is a continuous running one, after it has been started by a plc or background process, and until it has been stopped by PLC/BG process or safety devices.

    So I am doing it wrong all my programmers life:bawling:.

    On Fanuc and ABB robots one have to have a short wait instruction in a loop with only logic instructions without movements but Kuka Bots don't care about endless loops without wait instruction. Must have something to do with task scheduler of OS.

    Depends on what we are talking about by continuous running loop. If the robot is continuously moving and doing stuff, that's great. I just don't like having a continuous running loop to check for a start signal. A Wait instruction that waits on the signal instead of time achieves the same thing and you can see which line of code it is waiting on instead of a constant blur.

Advertising from our partners