CONTREX CX-1200 - Manual (Page 144)

5 - 51
FEEDFORWARD P1/1
Kff Auto En
Kff Automatic Enable (CP-364) enables the CX-1200 automatic adjustment of Kff (MP-48) at the specified KffAdjUpdt
(CP-363) interval in RUN with the loop closed.
1 = ON = Enabled
KffAdjUpdt
Kff Adjust Update (CP-363) sets the sampling period for the Kff calculation when it is enabled. KffAdjUpdt (CP-363)
is the time interval between each new Kff calculation and the automatic store to the Kff parameters depending on
whether Kff Auto En (CP-364) is enabled.
6 = 10 Min Update
5 = 1 Min Update
4 = 10 Sec Update
3 = 1 Sec Update (default)
2 = 500 mSec Update
1 = 250 mSec Update
Max Fb
Maximum Feedback (CP-329) and CO Max Volts (CP-271) are used to calculate a rough approximation for Kff (MP-48).
When a new Max FB (CP-329) value is entered, then Kff reflects a new value also.
Kff
Kff (MP-48) is the feedforward gain for the follower. It translates a follower EU/Time into an approximate voltage
output, which is then error-trimmed +/- to effect the desired speed. A reasonable accurate feedforward can minimize the
need for error trim action, thus improving the response of the control loop. It is automatically adjusted for any change
entered into CO Max Volts (CP-271), or Max Fb (CP-329). It is also adjusted automatically during feedforward Kff Auto
En (CP-364) mode.
FeedFwd
Feedforward (MP-35) displays the estimated voltage command to the drive required achieve the commanded RampedRef
(MP-31). It is usually the major portion of the CO Volts (MP-37) signal.
Intgrl
Integral (MP-34) displays the value of the integral term (i.e., integrated error times the Ki constant) of the PID compen-
sator. Intgrl (MP-34) is displayed in Volts. Intgrl (MP-34) is a conditioned error signal that serves to adjust the CO Volts
(MP-37) to help achieve the desired speed. It is part of the PID error correction algorithm.
Trim Out
Trim Out (MP-36) displays the value of the output of the PID compensator. Trim Out is displayed in Volts. Trim Out is
the sum of the conditioned error signals that, combined with the FeedFwd (MP-35), become the CO Volts (MP-37). Trim
Out is the combination of all three terms of the PID error correction algorithm.
CO Volts
Control Output Volts (MP-37) displays the present value, in volts, of the Control Output (CO_Sig) signal to the drive.
It is the combination of FeedFwd (MP-35) plus Trim Out (MP-36).