Sure, you can write values into a position variable in pulse, base, robot, tool, user, and if available master tool frame.
To do this on a User frame the frame has to either be defined manually or through a robot job.
The OP is asking about getting the current active user frame. There is not one except for jogging. The user frames are like a library or stack pointer. I point to the one I want to use.
correct,
You do not have an active state of a userframe for the sack of terminology you can say all taught userframes are active. you can use the active userframes in any related instruction but to have the number of UF during operation, you need to designate it with a variable instead of a constant value to have the opportunity to use its data somewhere else.
we are saying the same thing I guess.
regards,