I want my robot (RJ3iB) to only run in T1 mode when the fence is open, regardless of if the key switch is set to T1 or T2. I don't want to completely remove T2; we still use it on occasion when the fence is closed - I just want to make sure that if an operator goes inside the cell to teach that the robot is in T1. Is there a safe way to do this with variables or something or will I need to come up with a hardware solution?
With that age of robot, you will have to go with a hardware solution. There is nothing software wise that will be safety rated.
You may not be able to do this by modifying some values from the software. I've done something about this before, but I didn't get results. I made a small PLC connection directly to the ends of the T1 / T2 / Auto switch and used my own software for the scenario I wanted.
T1/T2/Auto Switch Pin out:
T1: 5+6 short, 7+8 short, 11+12 short
T2: 5+6 short, 7+8 short
AUTO: 1+2 short, 3+4 short, 9+10 short, 11+12 short
This does make me wonder how it might be possible to make the fence circuit toggle between T2 and T1, such that in the case of the mode switch in T1, you could operate from the teach pendant with or without the fence circuit broken, but if you have the mode switch set to T2 and the fence closed, it will operate as T2, and if the fence is open, it would operate as T1. This would actually be very useful as we have globally decided not to install the three mode switch for safety reasons, but this means that welds in coordinated motion must be tested in auto instead of teach (regular welds do not trigger the speed limit, but coordinated movements do, because we move the robot and the part together to reach the next position for each faster).
What manual would i find the Mode Switch wiring diagram and pin out in? I found one in the R-30iB electrical maintenance manual, but it was not an easy one to follow. Short of opening one of our cabinets and looking, i would like a rough idea how this could work and not be a safety violation.
If the UI is being used, can't *SFSPD set low when the fence is open and then the speed be determined by $SCR.$FENCEOVRD?