P
AGE
75
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 proportioning 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.
Instructions for determining rate are given in Section 4.3. Factory default is 0.0 Display code
rt1, rt2.
Relative Humidity
Stated as a percentage, Relative Humidity is the ratio of water vapor that is present in the air
to the maximum water vapor that the air can hold at the same temperature.
Second Output Position
This parameter is adjustable form -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 setpoint value is at a constant value for
the time period selected.
Wet Bulb
Is the temperature sensor that is kept moist (damp) and is connected to TB 5. This input is
necessary for Relative Humidity calculations.
Содержание MRC 7700
Страница 11: ...PAGE 11 FIGURE 2 2 FIGURE 2 3 Inductive Load 0 5 mfd 1000V 220 ohms 115V 1 4W 230V 1W Inductive Load R C MOV AC...
Страница 27: ...PAGE 27 HyAo rSP rSPu rSPL SPuL HyCo SPLL AtFr Prnd dFF PFF Pout Pou PoL Cru C C B CrL P1EC P2EC D...
Страница 29: ...PAGE 29 rrH PPC PIA F Crt Coo Com Optional Con CbS CAd1 CAd2 PAPu...
Страница 50: ...PAGE 50 Curve A unstable Curve B stable Curve C continuously cycling ultimate PB and period A C B Period...
