Delta RMC101 - Manual (Page 931)

Appendix G: Glossary
G-3
The PID LOOP is:
DO FOREVER
WAIT FOR NEXT TIME PERIOD
READ ACTUAL FROM POSITION OR PRESSURE SENSOR
E0 = TARGET - ACTUAL
U0p = Kp * E0
U0i = U1i + Ki * E0
U0d = ( E0 - E1 ) * Kd
U0 = U0p + U0i + U0d
E1 = E0
CALCULATE NEXT TARGET POSITION
END
Retracting
Going in the direction of decreasing encoder or transducer counts.
Soft Stop
An emergency stop condition where the drive ramps down to the null drive value.
SSI
Synchronous Serial Interface. A widely accepted controller interface to sensors and absolute
encoders. Position data is encoded in a 13- to 25-bit binary or Gray Code format and transmitted
over a high-speed synchronous interface.
Target Generator
The part of the motion control software that determines where the axis should be at any moment
using the requested position, speed, acceleration and deceleration provided by the user. A
different target generator is used for position control, speed control, gearing, synchronized moves
and pressure control.