text: <s>[INST] Servo Motors and Air Cylinders Hi, I'm looking for a way to make an air cylinder reach its extended position when my servo axis reaches a certain position. The cylinder and servo are 2 separate things. The servo is controlling an elevator type device (up/down) and the cylinder moves a knob in/out to the elevator. Since my cylinder takes n-seconds to reach its extended position (from retract) no mater what speed my servo goes, how can I make sure the cylinder reaches its extended position at the same time that my servo passes/stops at a certain position? I'm using an MAM for the servo. I'm thinking that after I start the MAM, there is a known motion profile for the servo drive controller to follow. Can I determine what position the servo will be at n-seconds before the end of the planned move? Or use some sort of output cam? Thanks, Denis. [/INST] It sounds like you do not have feedback from the air cylinder - you do not know its position as it moves. Without feedback, this is not going to be very precise. Your air cylinder speed is completely dependent on air pressure. Any changes or fluctuations are going to change your speed/position calculations. That said, if all you have is the time that it takes for the cylinder to extend, instead of using a Motion Axis Move (MAM) command, use a Motion Axis Time Cam (MATC) instruction. Look at the Logix help file for MATC to see how to use it. Also refer to the motion instruction reference manual: http://literature.rockwellautomation.com/idc/groups/literature/documents/rm/motion-rm002_-en-p.pdf \\n </s>