Ok, so I have two fanuc robots that pick out of and place into a furnace. I have it programmed to use a single MOVE point that is a position register set by a group input. That point is using a tool_offset to move into and out of the furnace. I set the speed of the motion instructions to 1500 mm/sec, but after running for 2 days, the motion instruction randomly changed from 1500 to 100 mm/sec and slowed our cycle time down considerably. I had to go back into the program and change it back to the previous speed. This was not the override speed which is always set at 70%. This was the movement speed of the motion instruction that suddenly changed. It is not possible for a production employee or anyone else to change it because we require a badge scan to edit the robots, and my badge is the only badge with the correct privileges' to edit. My question is, if I have a motion instruction like this, (L PR[1:Move Point] 1500mm/sec CNT50 Tool_Offset,PR[3:12 up Pos] ACC80) How could the 1500mm/sec change on its own to 100mm/sec? I went back and watched the camera footage of the time frame the change occurred, and you could see the change from one cycle to the next, but the pendant was never touched to be changed manually. Maybe a ghost did it because i have never heard of motion instructions changing on their own. I know that if override select is disabled, the robots will switch to their default speed after starting in auto, but i have never heard of the actual motion instruction changing.
Motion Instruction Changed
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white_raven -
December 31, 2020 at 6:46 PM -
Thread is marked as Resolved.
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I highly doubt a program changed itself. It just doesn't happen.
Could be someone has remote access to it and did a background edit on the program or uploaded a copy of the program.
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I highly doubt a program changed itself. It just doesn't happen.
Could be someone has remote access to it and did a background edit on the program or uploaded a copy of the program.
I thought the same thing at first, but after reviewing the camera footage from the furnace, no one had touched the pendant, and our network is restricted to IT and controls techs only. I am the only robotics tech in the facility, and the only one who can edit programs. Remote access is also restricted, and you must be logged into my account on our plant network in order to access the robot program/backup file folder on the Z drive. Also, I am the only person in the plant with the FANUC software on PC to even be able to edit programs remotely. Everything is locked down for this reason, and I am the only one with access. My only thought is a possible software glitch when the robot was performing an auto backup, that caused the motion instruction the robot was currently on to switch to the default setting (which is 100mm/sec). I came to this conclusion because of two things, 1.) the robots auto backup around this time frame and 2.) I could see from the footage that the robot physically changed its speed in the middle of the motion. It's very odd and after 10+ years of programming FANUC robots, this is the first time I've seen or heard of this happening.
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Sometimes when instructions misbehave, I delete them and then recreate them. Same with the PRs. It's fixed similar problems a few times.
If changing it back to 1500mm/sec done as a background edit, try in teach.
Move all backups on the network and replace with one where the instruction is correct.
Check the RAM disk (RD) and FROM (FR) and make sure there isn't a copy of the program there too.
Is it both robots?
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Sometimes when instructions misbehave, I delete them and then recreate them. Same with the PRs. It's fixed similar problems a few times.
If changing it back to 1500mm/sec done as a background edit, try in teach.
Move all backups on the network and replace with one where the instruction is correct.
Check the RAM disk (RD) and FROM (FR) and make sure there isn't a copy of the program there too.
Is it both robots?
I ended up rewriting the whole program and deleting the old one in case there was any more corrupted data. It was on both robots at about the same point in each of the programs. The only conclusion I could come up with was that the robots were in the process of an auto backup, when they were in motion to that point and something might have glitched and caused the motion instruction speed to default to the 100mm/sec. Either way, thanks for your help. It took some time to rewrite both programs, but its better to just eliminate the possibility of something else becoming corrupted.
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It was probably a PLC gremlin. They are very small and sneaky. They infiltrate our PLCs all the time. Just ask my colleague...