In the 6K, scaling commands need to be given only once and they are not valid inside of a program.
- SCLA is used to scale the acceleration in counts/unit
- SCLV is used to scale the velocity in counts/unit
- SCLD is used to scale the distance in counts/unit
- SCLMAS is used to scale the master encoder in counts/unit
To scale these values to inches or mm which can be done using the following equation (This equation assumes the user has a gearbox and leadscrew):
Pitch is defined as the distance between threads and lead is the distance traveled per revolution. They are equal to each other unless the leadscrew is a multi-threaded screw. For a multi-threaded screw the lead equals pitch times the number of threads.
SCLD=(drive resolution)*(gearbox ratio)/(lead or pitch)
This example assumes a leadscrew pitch of 0.2 in/rev with a gearbox reduction of 10:1, and a drive resolution set at 25000 steps/rev to scale the distance in inches. When the SCLD is set to this value the distance of D1 will represent 1 inch of travel.
For acceleration and velocity setting the SCLV and SCLA values to 1,250,000 will scale the velocity to in/sec and the acceleration to in/sec^2.
SCLMAS is used in following/gearing applications. See Ch6 of 6K Programmer Guide for further details/explanation/sample programs.