Programmable Limit Switch (PLS)
November 2005
QuickSilver Controls, Inc., adds a Programmable Limit Switch (PLS) output to its SilverDust™ controller/driver for servo control of NEMA 11, 17 and 23 frame servo motors.
The PLS command can be configured to use any of the motion controller’s possible 23 I/O to change states (i.e. high to low or low to high) at more than 150 pre-defined trigger points. A modulo may be selected to repeat the cycle.
The controller compares the motor position with the trigger position every 120 microseconds. When the trigger point is reached, the state of the I/O toggles automatically and the PLS command starts looking for the next trigger point.
Output triggering, trigger point values and number of trigger points may be changed dynamically even while the PLS command is running in the background. In factory automation, this could be used to change an output’s firing sequence for each part coming down the assembly line.
The above is an example of 4 triggers with a modulo of 16000.
Get Full Appliation Note (ZIP)