Red Lion TCU - Manual (Page 5)

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OPTIONS
HEATING AND COOLING CONTROL
The TCU has dual outputs for providing heating and cooling to those
processes that require them. Many extruder applications require both heating
and cooling to maintain accurate extruder barrel and die temperatures. The TCU
is easily configured for these applications.
Cooling Configuration Parameters
“CYC2” - Enter cooling time proportioning cycle time
“GAN2” - Enter cooling relative gain
“db-2” - Enter heat/cool deadband or overlap
HEATER CURRENT MONITOR
The Heater Current Monitor serves as a heater element fail sentry, so
operators can take corrective action before significant process errors occur in
the event of a failure. The actual heater current can be viewed in the secondary
display and/or a heater break alarm output can be programmed.
Heater Current Monitor Configuration Parameters
“HCur” - Enter full scale current of current transformer
ACt1”, “ACt2” - Program alarm(s) as heater break alarm
MOTORIZED VALVE POSITIONER
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” - Enter or measure valve closed position
“VPS2” - Enter or measure valve open position
“VUdt” - Enter Valve update time
“VPdb” - Enter valve control deadband
“VFAL” - Enter valve fail detect time
“Act1” - Program alarm as valve fail output
Velocity mode: “VUdt” - Enter Valve update time
“VOPt” - Enter valve open time
“VCLt” - Enter valve close time
“VONt” - Enter valve control deadband
(minimum on time)
INTERNAL CASCADE
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 it’s 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 (temperature) 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 TCU can accomplish two-process
cascade control.
Internal Cascade Configuration Parameters
“OPer” - Select cascade mode
“root” - Select second input square root linearization
“dPt2” - Select second input decimal point
“dSP1” - Enter scaling units of second input
“INP1” - Enter scaling units of second input
“dSP2” - Enter scaling units of second input
“INP2” - Enter scaling units of second input
“OPd2” - Output dampening of secondary
Internal Cascade Operational Parameters
“SP-2” - View secondary setpoint value
“Pb-2” - Enter secondary proportional band
“It-2” - Enter secondary integral time
“dt-2” - Enter secondary derivative time
EXTERNAL CASCADE
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” - Select ratio mode
“root” - Select second input square root linearization
“dPt2” - Select second input decimal point
“dSP1” - Enter scaling units of second input
“INP1” - Enter scaling units of second input
“dSP2” - Enter scaling units of second input
“INP2” - Enter scaling units of second input
“SPtr” - Local/Remote select options
External Cascade Operational Parameters
“rtio” - Remote setpoint ratio
“bIAS” - Remote setpoint bias
DSP
PAR
%PW
DEV
MAN
AL1
OPN
CLS
VALVE OPEN OUTPUT
VALVE CLOSE OUTPUT
SECOND INPUT
VALVE POSITION
MAIN INPUT
PROCESS
STEAM FLOW
VALVE FAIL
ALARM
AL1 OUTPUT
DSP
PAR
%PW
SEC
REM
OP1
AL1
AL2
LINEAR DC OUTPUT
SECOND INPUT
STEAM PRESSURE
STEAM
FLOW
PROCESS
MAIN INPUT
TEMPERATURE
(SECONDARY VARIABLE)
(PRIMARY VARIABLE)
DSP
PAR
%PW
DEV
MAN
OP1
AL1
AL2 OP1
REM
DSP
PAR
SEC
%PW
AL2
AL1
CONTROLLER CONTROLLER
LINEAR DC
(PRIMARY OUTPUT)
SECOND INPUT
REMOTE SETPOINT
STEAM
LINEAR DC
OUTPUT
MAIN INPUT
PROCESS TEMPERATURE
(PRIMARY VARIABLE)
PROCESS
MAIN INPUT
STEAM PRESSURE
(SECONDARY VARIABLE)
PCU TCU
SECONDARY PRIMARY
DSP
PAR
%PW
CUR
MAN
OP1
AL1
AL2
POWER
CONTROL
DEVICE
HEATING
ELEMENT
PROCESS
CURRENT TRANSFORMER
MAIN INPUT
TEMPERATURE
HEATER
CURRENT
MAIN
OUTPUT
(OP1)
HEATER BREAK
ALARM
AL1 OUTPUT
DSP
PAR
%PW
DEV
MAN
OP1
AL1
OP2
PROCESS
HEATING
CONTROL
COOLING
CONTROL
MAIN OUTPUT
(OP1)
SECOND OUTPUT
(OP2)
MAIN INPUT
TEMPERATURE
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