StarTalk™ DTM Help for StarPac 3 System
© Flowserve Corporation
Version 1.0.0 – Printed November 1, 2013
Determines the response of the controller to error. Reverse action will cause an air-to-open
valve to begin to close when the process variable is greater than the setpoint. Direct action has
the opposite effect. The following table gives some guidelines for control action settings:
Process Variable
Air-to-Open Valve
Air-to-Close Valve
Flow
Reverse
Direct
Upstream Pressure
Direct
Reverse
Downstream Pressure
Reverse
Direct
Differential Pressure
Direct
Reverse
Process Temperature
Depends on Installation
Depends on Installation
Auxiliary 4-20 Input
Depends on Installation
Depends on Installation
If the PID action is not set correctly, the controller will hold the valve either full open or full closed
and there will be no control.
Setpoint Source
This controls where the StarPac unit receives the valve command or controller setpoint
information. Integer register 40041 sets the setpoint source for how the unit receives control
information. Valid values are: 0 = 4-20 mA, 1 = Digital, 2 = Remote.
Digital
- Configures the unit so that integer register 40047 (SPI & II) or 40035 (SP 3) sets the
controller setpoint as a scaled integer if the StarPac unit is in Automatic mode. Integer register
40048 (SPI & II) or 40036 (SP 3) sets the valve position command as a scaled integer if the
StarPac unit is in Manual mode. The scale for digital source using the integer registers is fixed
for both position command and controller setpoint with 0 = -12.5 percent and 9999 = 112.5
percent. The valve command is defined as 0 percent = closed and 100 percent = open. See
Process maximum.
Analog
- Prompts the StarPac unit to use the 4-20 mA signal from the analog input as the
valve position command or as the controller setpoint, depending on whether or not the unit is
in Manual or Automatic mode. It can be set so that 4-20 mA = 0 to 100 percent or 100 to 0
percent, using integer register 40051 (SPI & II) or 40046 (SP 3) (1 = normal, 2 = inverted). See
Process maximum.
Remote
- Configures the unit so that floating point register 70551 (SPI & II) or 70705 (SP 3)
sets the controller setpoint in percent of maximum (See Process maximum) or the valve position
command in percent open, depending on the selected mode. Remote differs from Digital in
that the remote register must be updated within the number of seconds set in integer register
40111 (SPI & II) or 40109 (SP 3) or the unit will go into a Loss of Command Trip mode. When
the Loss of Command Trip occurs the system will initially hold the last setpoint if in auto, or the
last position if in Manual for the number of seconds specified in integer register 40052 (SPI & II)
or 40047 (SP 3). When the timer expires the valve will then ramp open or closed at the rate set
in floating point register 70321 (SPI & II) or 70491 (SP 3) (a negative rate will ramp closed and a
positive rate will ramp open).
