A command from an indexer
will produce clockwise (cw) or counter clockwise (ccw) pulses. SSRL uses pulse stretcher cards in driver
packages that will convert pulse/direction to cw/ccw pulses and adjust the
pulse width and sign if needed to match the motor driver.
The cw/ccw pulse mode is standard (not the pulse/direction mode) because it is viewed as fail safe.
A positive or increased pulse count will produce a cw rotation in an SSRL standard motor attached to a standard motor cable.
SSRL defines a cw rotation of the shaft when viewing the face of the stepping motor. The face of the motor is the side of the motor that is in direct contact to the component it is driving and from which the primary shaft emerges.
Limit switches will be wired with normally closed contact, a fail safe mode.