Avtron ADDvantage-32, Manual

Page: 138 / 290

Control Block Description
ADDvantage-32
4-76
2. Outputs Data Type Description
OUT:
Analog Output Signal
IERR: Analog Integral Error Value
MAX: Bit Indication Output is Clamped at High Value
MIN: Bit Indication Output is Clamped at Low Value
3. Implementation
If HOLD = LOW and PRE = LOW, then:
OUT = Propor Integral error values of block
where:
Proportional ERROR (PERR) = ERR × P
Integral Error (IERR) =
Old Integral Error Value +
⎟⎟
⎠
⎞
⎜⎜
⎝
⎛
Second
Time Sample
I
ERR
1
I is entered in seconds. If I is entered at less than 0.001 seconds, then I is set to zero.
The sample time is used to convert to the block execution rate where typically:
Armature Current Loop = 2.77 msec
Speed Loop = 8 msec
Tension Loop = 16 msec
If OUT > MAXL: The following sequence of events will occur:
The MAX bit = 1 (HIGH). The Proportional Error is set so OUT will not exceed
MAXL. If the Proportional Error = 0, the Integral Error will start to increase to
keep OUT below the MAXL limit.
If OUT < MINL: The following sequence of events will occur:
The MIN bit = 1 (HIGH). The Proportional error component is set so OUT will
not exceed MINL. If the Proportional Error = 0, the Integral Error component
will start to increase to keep OUT above the MINL limit.