Glossary, o - r – Watlow Series 922 User Manual
Page 80
80
WATLOW Series 922 User's Manual
Appendix
Glossary, O - R
OUT:
Select an output type. Action in response to the difference
between set point and process variable.
Output:
Action in response to difference between set point and process
variable.
Overshoot:
Condition whereby temperature exceeds set point due to initial
power up or process changes.
PB1C/PB2C:
A proportional temperature band for Channel 1 or Channel 2
expressed in degrees within which a temperature controller
proportioning function is active for cooling expressed in
degrees.
PB1H/PB2H::
A proportional temperature band for Channel 1 or Channel 2
expressed in degrees within which a temperature controller
proportioning function is active for heating. Expressed in
degrees.
P control:
Proportioning control.
Parameter:
A physical property whose value determines the response of
an electronic control to given inputs.
PD control:
Proportioning control with rate action.
PI control:
Proportioning control with auto-reset.
PID:
When ACCESS (1) is entered in the Series 922, the PID
parameters will appear. These parameters consist of Propor-
tional, Integral (auto reset), and Derivative (rate) actions.
PID control:
Proportioning control with auto-reset and rate.
Process Variable:
Thermal system element to be regulated, such as time
temperature, relative humidity, etc.
Programmed display
Displayed information which gives the operator/programmer
data:
the "programmed" or intended process information, i.e.,
intended set point, intended alarm limit, etc. See "Actual
displayed data."
Proportional band:
The span of temperature about the set point where time
proportional control action takes place.
Proportioning
control:
See Time proportioning control.
R1H/R2H:
Represents a high limit to set point for Channel 1 or Channel 2.
The default values are also the high limits of your input type.
R1L/R2L:
Represents a low limit to set point for Channel 1 or Channel 2.
The default values are also the low limits of your input type.
Rate:
Anticipatory action that senses the rate of change of tempera-
ture and compensates to minimize overshoot. Also "deriva-
tive."
Rate Band:
A thermal control band that defines where the rate (derivative)
function begins. A Watlow rate band occurs centered on set
point at one or more times the width of the proportional band.
RB1C/RB2C:
The thermal control band for cooling in Channel 1 or Channel 2
that defines where the rate (derivative) function begins.