Red Lion PCU - Manual (Page 43)

Print Options (PoPt)
Selecting YES for the print options allows the operator to scroll through
the available options using the PAR button. The up and down arrow keys
toggle between “yes” and “no” with “yes” enabling the option to be printed
when a print function occurs.
INP - Print Input Process Value
SEt - Print Setpoint Value
OPr - Print % Output Power Value
Pbd - Print % Proportional Band Value
INt - Print Integral Time Value
dEr - Print Derivative Time Value
AL1 - Print Alarm 1 Value
AL2 - Print Alarm 2 Value
dEv - Print Deviation From Setpoint Value
OFP - Print % Output Power Offset Value
r-P - Print Setpoint Ramp Rate Value
Crg - Print Relative Gain Value
Cdb - Print Deadband Value
OSt - Print Output Status
rAt - Print Remote Setpoint Ratio
bIA - Print Remote Setpoint Bias
rSP - Print Remote Setpoint Reading
IN2 - Print Second Input Reading
Pb2 - Print Proportional Band #2
It2 - Print Integral Time #2
dt2 - Print Derivative Time #2
SP2 - Print Internal Cascade Directed Setpoint
SECOND ANALOG INPUT MODULE (7-2N) (OPTIONAL)
The Second Analog Input can be configured as a Remote Setpoint Input or
as a Secondary Input for Internal Cascade control. As a Remote Setpoint, the
controller can operate as an External Cascade controller, Setpoint Slave
controller and as a Ratio controller. See
Cascade Control, page 56, for an
overview of cascade control.
Operation mode (OPEr)
The Second Analog Input must be configured for either Remote Setpoint
Operation or Internal Cascade Operation (single controller cascade).
rSP - Remote Setpoint
CSCd - Internal Cascade
Square Root Linearization (root)
In some cases it may be necessary to linearize the Second Analog input by
use of the square root function.
Selection of ‘yES’ results in the square root linearization of the Second
Analog Input(only). Selection of ‘NO’, results in linear scaling. The square
root linearization exhibits a 3% low cut point (17% of scaled reading) to
eliminate reading jitter at low flow rates. The following example illustrates
the scaling of the Second Analog Input with square root linearization.
Example: It is necessary to square root linearize the output of a differential
pressure transmitter to indicate and control flow. The defining equation is
F
= 278 D p, where D P = 0 - 500 PSI, transmitted linearly by a 4 - 20 mA
transducer. At full flow rate ( D P = 500 PSI), the flow is 6216 ft 3 /hr. The
following scaling information is used with the controller:
dPt2 = 0
root = yES
dSP1 = 0 Ft 3 /hr
INP1 = 4.00 mA
dSP2 = 6216 Ft 3 /hr
INP2 = 20.00 mA
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