Bulletin No. PCU-F
Drawing No. LP0338
Released 08/13
Tel +1 (717) 767-6511
Fax +1 (717) 764-0839
www.redlion.net
MODEL PCU - PROCESS CONTROL UNIT
SELF-DIAGNOSTICS
FULL PID CONTROL WITH REDUCED OVERSHOOT
OPTIONAL RS485 SERIAL COMMUNICATIONS INTERFACE
OPTIONAL DUAL ALARM OUTPUTS (USES OUTPUT MODULES)
OPTIONAL SECONDARY OUTPUT (USES OUTPUT MODULE)
OPTIONAL LINEAR 4 to 20 mA OR 0 to 10 VDC OUTPUT FOR
CONTROL OR PROCESS VALUE RE-TRANSMISSION
OPTIONAL MOTORIZED VALVE POSITION CONTROL AND
VALVE FAIL ALARM
OPTIONAL SECOND ANALOG INPUT FOR REMOTE SETPOINT
AND CASCADE CONTROL
OPTIONAL TYPE 4X/IP65 SEALED FRONT BEZEL
STATUS INDICATORS FOR OUTPUTS AND CONTROL MODES
PROGRAMMABLE USER INPUT (DIGITAL) FOR ADDED
FLEXIBILITY
MANUAL/AUTOMATIC AND LOCAL/REMOTE SETPOINT
CONTROL MODES
SETPOINT RAMPING FOR PROCESS STARTUP
PARAMETER SECURITY VIA PROGRAMMABLE LOCKOUTS
FIELD REPLACEABLE AND INTERCHANGEABLE OUTPUT
MODULES (Relay, Logic/SSR Drive and Triac)
C
UL
R
US LISTED
51EB
IND. CONT. EQ.
100 MSEC SAMPLING PERIOD WITH 0.15% ACCURACY
ON DEMAND AUTO-TUNING OF PID CONTROL SETTINGS
DUAL LED DISPLAYS FOR SIMULTANEOUS INDICATION OF
PROCESS VALUE AND SETPOINT OR SECOND ANALOG INPUT
ACCEPTS EITHER 0 to 10 VDC OR 0 to 20 mA DC INPUTS
DESCRIPTION
The PCU Controller accepts either 0 to 10 VDC or a 0 to 20 mA DC input
signal, precisely scales the process signal according to programmable scaling
points, and provides an accurate output control signal
(time proportional, linear,
or valve position)
to maintain a process at the desired control point. A
comprehensive set of easy to use program instructions allows the controller to
solve various applications.
The controller can operate in the PID control mode for both the main output
and optional secondary output, with on-demand auto-tune, that establishes the
tuning constants. The PID tuning constants may be fine-tuned by the operator
at any time and then locked-out from further modification. The controller
employs a unique overshoot suppression feature, which allows the quickest
response without excessive overshoot. The unit can be transferred to operate in
the manual mode, providing the operator with direct control of the output. The
controller may also be programmed to operate in the ON/OFF control mode
with adjustable hysteresis.
Dual 4-digit displays allow viewing of the process value and setpoint
simultaneously. Front panel indicators inform the operator of the controller and
output status. Replaceable and interchangeable output modules
(Relay, Logic/
SSR Drive, or Triac)
can be installed for the main control output, alarm
output(s) and secondary output.
DIMENSIONS In inches (mm)
Note: Recommended minimum clearance (behind the panel) for mounting clip installation is 5.5" (140) H x 2.1" (53.4) W.
5.41
(137.4)
PANEL CUT-OUT
1.77
+.02
-.00
(45
+.6
)
-.0
%PW MAN AL1
DEV OP1 AL2
3.80
(96.5)
3.60
(91.4)
3.62
-.00
(92
+.8
)
-.0
+.03
DSP
PAR
1.95
(49.5)
.40
(10.2)
5.29
(134.4)
1.75
(44.4)
1
OPTIONS
Optional dual alarms can be configured to activate according to a variety of
actions (Absolute HI or LO, Deviation HI or LO, Band IN or OUT and Valve
Fail Detect) with adjustable hysteresis. A standby feature suppresses the output
during power-up until the process stabilizes outside the alarm region. An
optional secondary output is available
(for processes that require cooling)
that
provides increased control accuracy and response.
A linear 4 to 20 mA or 0 to 10 VDC output signal is available to interface
with actuators, chart recorders, indicators, or other controllers. The output signal
can be digitally scaled and selected to transmit one of the following: % output
power, measurement value, process measurement value deviation or setpoint
value. Valve Positioner and Second Analog Input Models have the adjustable
output demand dampening, output deadband and output update time parameters
to expand the versatility of the PCU to control devices.
The optional Motorized Valve Positioner directly controls the position of a
valve by the use of twin outputs (open and close) to control the direction of
motor rotation. The motor position defines the opening position of the valve.
Two control modes are possible: position control, that makes use of the
slidewire feedback signal supplied with the positioner and velocity control, in
which no slidewire feedback signal is used. Parameters are provided to adjust
the operation of the valve. These include:
-
-
-
-
-
Valve activity hysteresis
Valve update time
Variable control dampening
Slidewire signal fail action
Adjustable valve position limits
2.
POWER:
Switch selectable 115/230 VAC (+10%, -15%) no observable line
variation effect, 48 to 62 Hz, 10 VA.
3.
ANNUNCIATORS:
LED Backlight Status Indicators (Model dependent):
%PW
DEV
OP1
AL1
AL2
OP2
OPN
CLS
SEC
MAN
REM
- Lower auxiliary display shows power output in (%).
- Lower auxiliary display shows deviation
(error)
from process setpoint.
- Main control output is active.
- Alarm #1 is active.
- Alarm #2 is active
(for Dual Alarm Option).
- Secondary output is active
(for Secondary Output Option).
- Valve positioner OPEN output is active
(for Valve Positioner Option).
- Valve positioner CLOSE output is active
(for Valve Positioner Option).
- Lower auxiliary display shows second analog input
(for Second Analog Input Option).
- Flashing: Controller is in Manual control mode.
- ON: controller is in remote setpoint mode
(Second Analog Input Option).
- OFF: controller is in local setpoint mode
(Second Analog Input Option).
- Flashing: controller is in Manual control mode
(Second Analog Input Optional).
“-...”
“SLid”
“VALV”
- Appears when display values exceed - display range.
- Appears when loss of slidewire signal is detected.
- Appears when valve actuator error is detected.
The Valve Positioner PCU achieves tight process control, yet minimizes
unnecessary valve activity. An alarm event output or display alarm can be
programmed under loss of slidewire feedback or under valve fail detection.
The optional Second Analog Input (0 to 20 mA DC) can be configured as a
remote setpoint signal or as a secondary process signal. Configuration of the
second analog input as a remote setpoint signal allows ratio control, master
setpoint/multiple slave operation, and the ability to cascade the PCU with
another controller (external cascade). Configuration of the second input as a
secondary process signal allows operation as a two-process cascade controller
within a single unit (internal cascade). In either control mode, parameters are
provided to scale, configure, communicate and monitor the activity of both
analog inputs. A square law linearizer function can be used to linearize signals
derived from flow transmitters.
The optional RS485 multidrop serial communication interface provides two-
way communication between a PCU unit and other compatible equipment such
as a printer, a programmable controller, or a host computer. In multipoint
applications the address number of each unit on the line can be programmed
from zero to ninety-nine. Up to thirty-two units can be installed on a single pair
of wires. The Setpoint value, % Output Power, Setpoint Ramp Rate, etc. can be
interrogated or changed by sending the proper command code via serial
communications. Alarm output(s) may also be reset via the serial communications
interface option.
An optional Type 4X/IP65 rated bezel is available for wash down and/or dirty
environments, when properly installed. Modern surface-mount technology,
extensive testing, plus high immunity to noise interference makes the controller
extremely reliable in industrial environments.
4.
CONTROLS:
Four front panel push buttons for modifying and setup of
controller functions and one external input for parameter lockout or other
functions.
5.
SIGNAL INPUT:
Sample Period:
100 msec typ.
Response Time:
300 msec typ.
(to within 99% of final value w/step input)
Signal Overdrive Threshold:
10 V Range:
13 V typ.
20 mA Range:
26 mA typ.
Signal Overdrive Response:
Main Control Output:
Programmable preset output
Display:
“SENS”
Alarms:
Upscale drive
DC Linear:
Programmable preset output
Normal Mode Rejection:
40 dB typ. @ 50/60 Hz
(improves with increased
digital filtering).
Common Mode Rejection:
100 dB typ., DC to 60 Hz
Protection:
Input overload 120 VAC for 30 seconds.
Range And Accuracy:
SIGNAL RANGE
ACCURACY (% OF
UNSCALED
READING)
MAXIMUM
INPUT
INPUT
RESOLUTION
IMPEDANCE
0 to 10 VDC
0 to 20 mADC
±(0.15% + 3 mV)
±(0.15% + 6 µA)
300 VDC
200 mADC
1M
Ω
10
Ω
10 mV
10 µA
SAFETY SUMMARY
All safety related regulations, local codes and instructions that appear in the
manual or on equipment must be observed to ensure personal safety and to
prevent damage to either the instrument or equipment connected to it. If
equipment is used in a manner not specified by the manufacturer, the protection
provided by the equipment may be impaired.
Do not use the PCU to directly command motors, valves, or other actuators
not equipped with safeguards. To do so, can be potentially harmful to persons
or equipment in the event of a fault to the unit. An independent and redundant
limit indicator with alarm outputs is strongly recommended. The indicators
should have input sensors and AC power feeds independent from other
equipment.
SPECIFICATIONS
1.
DISPLAY:
Dual 4-digit
Upper Process Display:
0.4" (10.2 mm) high red LED
Lower Auxiliary Display:
0.3" (7.6 mm) high green LED
Display Messages (Model dependent):
“OLOL”
“ULUL”
“SENS”
“....”
- Appears when measurement exceeds +105% input range.
- Appears when measurement exceeds -5% input range.
- Appears when measurement exceeds “OLOL” & “ULUL”
range.
- Appears when display values exceed + display range.
6.
OUTPUT MODULES [Optional] (For All Output Channels):
Relay:
Type:
Form-C
(Form-A with some models. See Ordering Information.)
Rating:
5 Amps @ 120/240 VAC or 28 VDC
(resistive load),
1/8 HP @
120 VAC
(inductive load)
max.
Life Expectancy:
100,000 cycles at max. load rating.
(Decreasing load
and/or increasing cycle time, increases life expectancy).
Logic/SSR Drive:
Can drive multiple SSR Power Units.
Type:
Non-isolated switched DC, 12 VDC typ.
Drive:
45 mA max.
Triac:
Type:
Isolated, Zero Crossing Detection
Rating:
Voltage:
120/240 VAC
Max. Load Current:
1 Amp @ 35°C
0.75 Amp @ 50°C
Min. Load Current:
10 mA
Off State Leakage Current:
7 mA max. @ 60 Hz
Operating Frequency:
20 to 400 Hz
Protection:
Internal Transient Snubber, Fused
7.
MAIN CONTROL OUTPUT:
Control:
PID or ON/OFF
Output:
Time proportioning or linear DC
Hardware:
Plug-in, replaceable output modules
Cycle time:
Programmable
Auto-tune:
When selected, sets proportional band, integral time, and
derivative time values.
Signal Overdrive Action:
Programmable
2
SPECIFICATIONS (Cont’d)
8.
SECONDARY OUTPUT (Optional):
Control:
PID or ON/OFF
Output:
Time proportioning or linear DC
Hardware:
Plug-in, replaceable output modules
Cycle time:
Programmable
Proportional Gain Adjust:
Programmable
Deadband Overlap:
Programmable
9.
LINEAR DC OUTPUT (Optional):
With digital scale and offset,
programmable deadband and update time.
4 to 20 mA:
Resolution:
1 part in 3500 typ.
Accuracy:
±(0.1%
of reading + 25
µA)
Compliance:
10 V
(500
Ω
max. loop impedance)
0 to 10 VDC:
Resolution:
1 part in 3500 typ.
Accuracy:
±(0.1%
of reading + 35 mV)
Min. Load Resistance:
10 KΩ
(1 mA max.)
Source:
% output power, setpoint, deviation, or process value
(Available for OP1 or OP2, but not both.)
10.
MOTORIZED VALVE POSITIONER (Optional):
Two Outputs:
Valve open and valve close or Linear DC
(optional)
Hardware:
Plug-in, replaceable output modules
Three Inputs:
Slidewire feedback, signal fail detect
(Isolated from main
input)
Slidewire Resistance:
100
Ω
to 100 KΩ
Slidewire Exciting Voltage:
0.9 VDC typ.
Slidewire Fail Action:
programmable
Control Mode:
Position mode
(with slidewire)
and velocity mode
(w/o
slidewire).
Control Deadband:
1% to 25.0% (position mode)
0.1 to 25.0 seconds (velocity mode)
Update Time:
1 to 250 seconds
Motor Time (open, close):
1 to 9999 seconds
Position Limits:
Adjustable 0.0 to 100.0% of valve stroke
Valve Fail Time:
Off to 9999 seconds
Alarm mode:
Dual acting; loss of slidewire feedback signal and valve fail
detection
11.
SECOND ANALOG INPUT:
Range:
0 to 20 mA (Isolated from main input)
Overload:
100 mA
MIN
(steady state)
Input Resistance:
10
Ω
typ.
Voltage Drop (@ 20 mA):
0.2 V typ.
Accuracy:
0.15% of reading ±10 µA ±1 LSD
Scale Range:
-999 to 9999
12.
SERIAL COMMUNICATION:
Type:
RS485 Multi-point, Balanced Interface
Communication Format:
Baud Rate:
Programmable from 300 to 9600
Parity:
Programmable for odd, even, or no parity
Frame:
1 start bit, 7 data bits, 1 or no parity bit, 1 stop bit
Unit Address:
Programmable from 0 to 99, max. of 32 units per line
Transmit Delay:
100 msec min., 200 msec max.
RS485 Common:
Isolated from signal input common
Auto Print Time:
Off to 9999 seconds between print-outs
13.
USER INPUT (Optional):
Internally pulled up to +5 VDC.
V
IN
= 5.25 VDC
MAX
, V
IL
= 0.85 V
MAX
; V
IH
= 3.0 V
MIN
,
Available on all second input (MVP & ANA) models, and on models with
RS485.
Response Time:
100 msec max.
Functions:
Program Lock
Integral Action Lock
Auto/Manual Mode Select
Setpoint Ramp Select
Reset Alarms
Print Request
Local/Remote Setpoint Select
14.
ALARMS (Optional):
Hardware:
Plug-in, replaceable output module
Modes:
Absolute high acting
Absolute low acting
Deviation high acting
Deviation low acting
Inside band acting
Outside band acting
Valve fail
Second Analog Input monitoring
Reset Action:
Programmable; automatic or latched
Standby Mode:
Programmable; enable or disable
Hysteresis:
Programmable
3
Signal Overdrive Action:
Upscale
Annunciator:
LED backlight for “AL1”, “AL2”,
(Alarm #2 not available
with secondary output or motorized valve position option.)
15.
ENVIRONMENTAL CONDITIONS:
Operating Temperature Range:
0 to 50°C
Storage Temperature Range:
-40 to 80°C
Vibration to IEC 68-2-6:
Operational 5-150 Hz, 1 g
Shock to IEC 68-2-27:
Operational 5 g
Span Drift
(maximum):
100 ppm/°C, main input; 150 ppm/°C, second input
Zero Drift
(maximum):
4 to 20 mA DC Range:
0.5 µA/°C
0 to 10 VDC Range:
0.2 mV/°C
Second Input:
2 µA/°C
Relative Humidity:
Less than 85% RH (non-condensing)
Altitude:
Up to 2000 meters
16.
ISOLATION BREAKDOWN RATINGS:
All inputs and outputs with respect to AC line:
2300 V
MIN
Analog Outputs, Second Analog Input or Slidewire Input with respect to
main input:
500 V
MIN
17.
CERTIFICATIONS AND COMPLIANCES:
CE Approved
EN 61326-1 Immunity to Industrial Locations
Emission CISPR 11 Class A
EN 61010-1
RoHS Compliant
UL Recognized Component: File #E156876
UL Listed: File #E137808
Type 2 Enclosure rating (Face only) for PCU0
Type 4X/IP65 Enclosure rating (Face only) for PCU1
Refer to EMC Installation Guidelines section of the manual for additional
information.
18.
CONNECTION:
Jaw-type terminal block
Wire Range:
12-30 AWG copper wire
Torque:
5-7 inch-lbs (56-79 N-cm)
19.
CONSTRUCTION:
Front Panel:
Flame and scratch resistant tinted plastic
Case:
High impact black plastic. (Mounting collar included)
Type 4X/IP65 model only:
Sealed bezel utilizing two captive mounting
screws (panel gasket included) This unit is rated for Type 4X/IP65 indoor
use. Installation Category II, Pollution Degree 2
20.
WEIGHT:
1.3 lbs (0.6 kgs)
BASIC OPERATION
The PCU controls a process by measuring the input signal and then calculating
a control output power value by use of a modified PID control algorithm. The unit
controls the system with the new output power value to keep the process at
setpoint. The PID control algorithm incorporates features that provide for high
control accuracy and low overshoot from process disturbances.
FRONT PANEL FEATURES
In the normal operating mode, the unit displays the scaled process value in the
upper display. One of four other parameters can be viewed in the lower display:
- Setpoint
- % Power Output
- Deviation
- Second Input Process Value
The parameters can be scrolled through by pressing the DSP button. If
enabled, the control setpoint or power output (manual mode only) can be
directly modified in this mode.
In the normal operating mode, parameters are selected by use of the PAR
button and modified by use of the UP and DOWN buttons. Parameters are then
entered by the PAR button, which advances the user to the next parameter.
Pressing the DSP button immediately returns the controller to the normal
operating mode when making a parameter change. The controller’s configuration
and parameter settings are stored in an internal E
2
PROM device.
HARDWARE FEATURES
The fast 100 msec input sampling rate provides quick controller response to
a process disturbance, thus providing excellent process control. Measurement
accuracy of 0.15% or better, provides closer process control conforming to the
desired control setpoint value. The unit accepts either a 0 to 10 VDC or a 0 to
20 mA DC input signal. The AC input power is switch selectable, allowing the
unit to operate from either 115 VAC or 230 VAC. Since the controller is
serviceable from the front of the panel, the output modules may be easily
changed or replaced without disturbing the wiring behind the panel. No
re-programming is required when changing or replacing modules.
The optional Type 4X/IP65 rated model utilizes two bezel securing screws
and a neoprene gasket to guarantee a water tight seal, when properly installed.
The standard model simply requires pressing a latch to remove the unit.
Low-drift, highly stable circuitry ensures years of reliable and accurate
process control. The recommended two-year re-calibration interval is easily
accomplished via the programming menu.
OPTIONS
RATIO CONTROL
SECOND INPUT
UNCONTROLLED
FLOW
FLOW A
%PW REM AL1
SEC OP1 AL2
FLOW C = FLOW A + FLOW B
DSP
LINEAR DC
OUTPUT
MAIN INPUT
CONTROLLED
FLOW
FLOW B = [RATIO * FLOW A] + BIAS
PAR
SETPOINT FEATURES
The controller setpoint can be protected from out of range values by
programming the setpoint range limit values. Additionally, safeguards from
inadvertent data entry can be programmed.
The setpoint ramp feature ramps the setpoint value at start-up or any time a
setpoint change is made, at a user programmable rate. This feature reduces
shock to the process and helps to minimize overshoot. The setpoint may also be
transmitted by the optional linear DC output for slave control loops.
The second analog input may be configured as a remote setpoint. As such, the
controller is easily switched from local/remote setpoint operation via the front
panel or user input. Ratio and bias parameters provide on-line scaling of the
remote setpoint. Absolute limit values and maximum rate of change of the
remote setpoint further enhance controller flexibility.
The PCU configured for ratio operation controls a process as a ratio of
another process or to another variable. Ratio control is commonly used for flow
applications, however, any two process variables can be controlled in a
ratio mode.
Ratio Control Configuration Parameters
“OPEr”
“root”
“dPt2”
“dSP1”
“INP1”
“dSP2”
“INP2”
“SPtr”
“InPt”
- Select ratio mode
- Select second input square root linearization
- Select second input decimal point
- Enter scaling units of second input
- Local/Remote Select options
- Program User Input for Local/Remote
Setpoint selection
- Remote setpoint ratio
- Remote setpoint bias
INPUT FEATURES
A programmable input filter can be used to stabilize readings from a process
with varying or oscillating characteristics, helping to provide better process
control. Programmable scaling points allow the controller to display in any
engineering unit; flow, level, pressure, etc. Scaling points are used in
conjunction with the programmable rounding increment to stabilize a jittery or
otherwise hard to read process signal for better indication.
The programmable User Input can be used to control a variety of functions,
such as auto/manual transfer of the controller, reset alarm output(s), etc.
The second analog input has independent scaling parameters to match the
units of other processes or transmitters, or to match the controller’s range.
Ratio Control Operational Parameters
“rtio”
“bIAS”
MOTORIZED VALVE POSITIONER
AL1 OUTPUT
VALVE FAIL
ALARM
STEAM FLOW
VALVE OPEN OUTPUT
VALVE CLOSE OUTPUT
OUTPUT FEATURES
Programmable output power limits provide protection for processes where
excessive power can cause damage. Automatic signal overdrive detection, for
fail-safe operation, causes the controller to default to a programmed output
power (upscale or downscale burnout). With adjustable time proportioning
cycle time, and programmable DC linear output, the controller can satisfy a
wide variety of output requirements.
Programmable dampening output hysteresis and output update time parameters
can dramatically reduce actuator activity without degrading control accuracy.
The RS485 Communication option allows the user to access various
controller parameters such as the setpoint, % output power, % proportional
band, etc. The controller may be set up to transmit various parameters at a
programmable automatic print rate.
%PW MAN OPN
DEV AL1 CLS
DSP
SECOND INPUT
VALVE POSITION
MAIN INPUT
PROCESS
PAR
AUTO-TUNE
The motorized valve positioner controls the position of a valve directly, by
use of
“open”
and
“close”
control outputs. The slidewire feedback signals of
the valve may optionally be connected to the controller. Alternatively, the
controller may be configured for linear input valve control using the 4 to 20 mA
DC output.
Motorized Valve Positioner Configuration Parameters
Position mode:
“VPS1”
“VPS2”
“VUdt”
“VPdb”
“VFAL”
“Act1”
“VUdt”
“VOPt”
“VCLt”
“VOnt”
-
-
-
-
-
-
-
-
-
-
The PCU has an auto-tune feature that, on demand, automatically determines
the PID control parameters for a particular process. After completion of auto-
tune, the PID parameters are automatically optimized for that process and
loaded into nonvolatile memory. The operator may view and modify the
parameters as desired.
Auto-tune may be invoked either at start-up or at setpoint, depending on the
process requirements. An auto-tune programmable dampening factor produces
various levels of process control and response characteristics.
Velocity mode:
Enter or measure valve closed position
Enter or measure valve open position
Enter Valve update time
Enter valve control deadband
Enter valve fail detect time
Program alarm as valve fail output
Enter Valve update time
Enter valve open time
Enter valve close time
Enter valve control deadband
(minimum on time)
4
INTERNAL CASCADE
STEAM
FLOW
EXTERNAL CASCADE
PRIMARY
CONTROLLER
LINEAR DC
(PRIMARY OUTPUT)
STEAM
SECOND INPUT
REMOTE SETPOINT
SECONDARY
CONTROLLER
LINEAR DC OUTPUT
%PW REM AL1
SEC OP1 AL2
SECOND INPUT
STEAM PRESSURE
(SECONDARY VARIABLE)
MAIN INPUT
(PRIMARY VARIABLE)
%PW MAN AL1
DEV OP1 AL2
LINEAR DC
OUTPUT
%PW REM AL1
SEC OP1 AL2
DSP
DSP
DSP
PROCESS
PAR
PAR
MAIN INPUT
STEAM PRESSURE
(SECONDARY VARIABLE)
PAR
TCU
PCU
MAIN INPUT
PROCESS TEMPERATURE
(PRIMARY VARIABLE)
PROCESS
Cascade control allows the process to be divided into two control loops: the
primary control loop and the secondary control loop. The secondary loop receives
its setpoint from the primary loop to control an intermediate variable (steam
pressure). The control level of the intermediate variable is the input to the primary
process. The primary loop (main input) controller maintains loop regulation by
manipulating the setpoint of the secondary controller. The setpoint of the
secondary controller, in turn, changes the intermediate variable. The secondary
loop can react faster to disturbances of the intermediate variable, thereby
minimizing the effects to the primary control loop. Control loops cascaded in such
a manner provide greater control quality than would be possible with single loop
control. A single PCU can accomplish two-process cascade control.
Internal Cascade Configuration Parameters
“OPEr”
“root”
“dPt2”
“dSP1”
“INP1”
“dSP2”
“INP2”
“OPd2”
- Select cascade mode
- Select second input square root linearization
- Select second input decimal point
Similar to internal cascade control, external cascade control differs by the
employment of two controllers, one of which is equipped with a second analog
input configured as a remote setpoint. A PCU controls the secondary loop, while
a TCU controls the primary loop.
External Cascade Configuration Parameters
“OPEr”
“root”
“dPt2”
“dSP1”
“INP1”
“dSP2”
“INP2”
“SPtr”
“rtio”
“bIAS”
- Select ratio mode
- Select second input square root linearization
- Select second input decimal point
- Enter scaling units of second input
- Local/Remote select options
- Remote setpoint ratio
- Remote setpoint bias
External Cascade Operational Parameters
- Enter scaling units of second input
- Output dampening of secondary
Internal Cascade Operational Parameters
“SP-2”
“Pb-2”
“It-2”
“dt-2”
-
-
-
-
View secondary setpoint value
Enter secondary proportional band
Enter secondary integral time
Enter secondary derivative time
SETPOINT MASTER CONTROL
LINEAR DC OUTPUT SETPOINT RE-TRANSMISSION
Setpoint Master Control allows automatic setpoint changes to
slave controller units (up to 50 units total) from a master PCU
controller. The linear DC output of the master is looped with the
second analog input of the slave PCU controllers. Each slave unit
can have unique remote setpoint ratio and bias values.
Setpoint Slave Configuration Parameters
“OPEr”
“root”
- Select remote setpoint mode
- Select second input square root
linearization
- Select second input decimal point
MASTER
UNIT
SECOND INPUT
REMOTE SETPOINT
SLAVE
UNIT #1
SECOND INPUT
REMOTE SETPOINT
SLAVE
UNIT `N'
(UP TO 50)
“dPt2”
“dSP1”
“INP1”
“dSP2”
“INP2”
“SPLO”
“SPHI”
“SPrP”
- Enter scaling units of second input
- Limit range of remote setpoint
- Limit rate of change of remote
setpoint
- Second input ratio
- Second input bias
%PW MAN AL1
DEV OP1 AL2
%PW REM AL1
SEC OP1 AL2
%PW REM AL1
SEC OP1 AL2
DSP
DSP
DSP
PAR
PAR
PAR
Setpoint Slave Operational Parameters
“rtio”
“bIAS”
MAIN
INPUT
MAIN
INPUT
MAIN
INPUT
PROCESS #1
PROCESS #2
PROCESS "N"
5
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