Delta RMC101 User Manual
Page 930
RMC100 and RMCWin User Manual
G-2
MDT
Magnetostrictive Displacement Transducer. A device that senses position by sending an electron
pulse down a wave guide. A twist is imparted on the wave guide as the pulse reaches the
magnetic field of a magnet. The twist takes time to be sensed at the transducer head. It is this
time is proportional to the distance between the transducer head and the magnet. The RMC
measures this time to determine the distance.
Note:
Balluff and Temposonics rods are both MDTs whereas any linear measurement device
can be a LDT.
Open Loop Mode
The drive output is set to a value without any corrective action taken by the PID routine.
PID
Proportional Integral Derivative. A simple algorithm used by the motion controller to reduce the
error between the target and actual position, pressure, etc. The three words of this acronym
represent the three types of gains used for controlling a system. See PID Loop below.
PID Loop
The process of repeatedly executing the PID routine
Error: = Target - Actual
E0: Current Error, Error for current Target and Actual
E1: Previous Error, Error for previous Target and Actual
U0: Current output
U1: Previous output
Kp: Proportional Gain
Ki: Integral Gain
Kd: Differential Gain
Proportional Term: U0p = Kp * E0
Integral Term: U0i = U1i + Ki * E0
Differential Term: U0d = ( E0 - E1 ) * Kd
The Sum is: U0 = U0p + U0i + U0d