Delta MMC120 - Manual (Page 32)

Motion Control Parameters MMC120 Linear Motion Control Module
32 Delta Computer Systems, Inc. 360/254-8688
PROPORTIONAL GAIN = 0.1 millivolt per unit of Position Error
Proportional drive is defined as:
Proportional Drive = PROPORTIONAL GAIN x Position Error
INTEGRAL GAIN (Default: 1) Range: 0 to 65535
The INTEGRAL GAIN is used to control the amount of drive provided by the integrator. The integrator adds
the position error to an accumulator every millisecond.
INTEGRAL GAIN is defined as:
INTEGRAL GAIN = 0.1 millivolt per 1024 counts of accumulated Position Error
Integral Drive is defined as:
Integral Drive = INTEGRAL GAIN x Accumulated Counts
DIFFERENTIAL GAIN (Default: 0) Range: 0 to 65535
The DIFFERENTIAL GAIN field is used to control the differentiator. The change in error is multiplied by the
DIFFERENTIAL GAIN value to get the differentiator drive term.
DIFFERENTIAL GAIN is defined as:
DIFFERENTIAL GAIN = 0.1 millivolt per change in Position Error
Differential Drive is defined as:
Differential Drive = (E0
(TARGET POSITION - ACTUAL POSITION)
- E1
(TARGET POSITION - ACTUAL POSITION)
)
x DIFFERENTIAL GAIN
where E0 is the position error in the first time period and E1 is the position error in the second time period.
(E0 - E1) is the change in position error between the two time periods.
EXTEND FEED FORWARD (Default: 100) Range: 0 to 65535
FEED FORWARD is an open loop compensation which is proportional to the TARGET SPEED of the axis.
This value is expressed in terms of millivolts per 1,000 Position Units per second. EXTEND FEED
FORWARD drive is added to the output only when the axis is extending. The drive output provided by the
EXTEND FEED FORWARD is determined as follows:
EXTEND FEED FORWARD x TARGET SPEED
Feed Forward Drive =

1,000
TIP: After the axis has made a complete move without oscillations or overdrive errors, use the 'F' command to
automatically set the FEED FORWARD value.
RETRACT FEED FORWARD (Default: 100) Range: 0 to 65535
Same as EXTEND FEED FORWARD, except it is used when retracting.
NOTE: Retracting is the direction that returns decreasing COUNTS.