AB Control Logic Motion Time Cam MATC Time Units

Hello All,
I have been working on a pick and place machine using the ControlLogix motion.

Two hydraulic servo axis for the pick and place motion are "cammed" to an encoder driven virtual axis via a MAPC (motion axis position cam) instruction.

I want to try using a MATC (motion axis time cam) instruction as an alternative to the position cam. The position increments of the master axis for the MAPC are larger than ideal, and since the conveyor is running at a constant speed, the MATC should provide smoother camming action than the MAPC.

I did not think of using the MATC when I had the machine to myself for testing. Later, with the machine in producton, I thought it I would try it.

Problem is, I could not find what "Time Units" AB uses for the master time. Are they in seconds, or System Time units (uSecs perhaps) Can anybody shed some light on this?

Cheers,
PL

I just asked our motion specilaist, who was plyaing with that very instruction on one of our demos yesterday. He says it is in seconds.

Thanks mgvol.
I thought it was seconds, but didn't want to risk an online change with the possiblity of throwing a wrench into the machine!
Cheers,
PL

Smooth motion

For smoother motion in Clx I look at a number of things
1) Master axis - enough counts per mm, I have found it easier to replace the master encoder with a higher count encoder (eg 4096 counts with 16384 counts) or move the encoder to the back of the motor (only if positive drive to conveyor ie tooth belts, chain, gear box. never for V belts)
2) IS the "Master Position Filter" enabled - in the axis properties of the slave axis (adds a lag to positioning especially during accel and decel) this could remove some roughness in a feedback only master
3) do I have Jerk control in the CAM profile - ie the acceleration profile is continuous. see Green line below