West Control Solutions MRC 7000 Profiler Manual - Manual (Page 73)

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Rate (Derivative)
This parameter is adjustable from 0.0 to 10.0 minutes and specifies how the control action
responds to the rate of change in the process variable. For example, if the process variable is
rising rapidly to setpoint, power is turned off sooner than it would be if the rise were slow. In
effect, derivative action anticipates lags within the system and shifts the proportioning band by
an amount determined by the rate of change of the input sensor.
Magnitude of the shift is determined by a derivative time constant. If the time constant is, say,
.1 minute (6 seconds), for every unit per second rate of change of the process variable at the
sensor, the proportiong band is moved 7 units in the direction that helps control. Likewise, if
the time constant is 1 minute (60 seconds), for every unit per second rate of change of the
process variable at the sensor, the proportioning band is moved 60 units in the direction that
helps control. Factory default is 0.0 Display code rAtE.
Second Output Position (SoP)
This parameter is adjustable from -1000 to 1000 units and represents a shift or offset of the
on-off actuation points or proportional band for the second output relative to the normal
position. A positive value creates a gap where no control outputs are on, a negative value
creates an overlap of control outputs (if the first output position is at the normal position).
Second Output Position also shifts the proportional band with respect to the process value
range outside of which integral action is highlighted (reset-windup inhibit). Factory default is 0.
Display code SoP.
Segment
A segment refers to a part of a profile. A segment consists of a Ramp and a Soak section.
Soak
A Soak is the section of a profile segment where the setoint value is at a constant value for
the time period selected.