Avtron ADDvantage-32, Manual

Page: 142 / 290

Control Block Description
ADDvantage-32
4-80
If OUT > MAXL or H-UP = 1: The CMX bit = 1 (HIGH).
If OUT < MINL or H-DN = 1: The CMN bit = 1 (HIGH).
If H-UP = HIGH and PRE = LOW, then:
The Integral Error component cannot increase in the positive direction until the
H-UP input goes low. Positive ERR values are ignored by the integral error
component. The integrator hold up input is used to keep the integrator from
increasing in the positive direction during major process disturbances. Note that
the Proportional Error is not affected by the H-UP input.
If H-DN = HIGH and PRE = LOW, then:
The Integral Error component cannot increase in the negative direction until the
H-DN input goes low. Negative ERR values are ignored by the integral error
component. The integrator hold down input is used to keep the integrator from
increasing in the negative direction during major process disturbances. Note that
the Proportional Error is not affected by the H-DN input.
If PRE = HIGH, then:
The Integral Error component is set to the PREL value and the Proportional Error
component is set to zero so that:
OUT = IERR = PREL
The IERR output is equal to the integrator component and can be used for
diagnostic purposes.