Emerson Process Management ControlWave XFC - Manual (Page 110)

F-8 / Appendix F CI-ControlWave XFC
F.5.4.1.1 Enabling the Nomination Function
The nomination function runs once per calculation cycle after the volume and energy
accumulations have been updated by the ControlWave XFC. To setup and enable this
feature follow the steps below.
1. Setup of the nominations feature depends on the desired control mode selection, i.e., the
Fast approach mode or PID mode. Fast approach mode is the default mode for
nominations. If the desired control mode is the Fast approach mode, proceed to step 2;
however, if the desired control mode selection is the PID mode, you must first program
all the PID tuning parameters such as gain and integral. Note: DON’T enable the PID
flow control algorithm or the ControlWave XFC will automatically disable nomination.
When properly configured the ControlWave XFC will automatically enable the PID
flow control algorithm during nomination periods.
2. Select the Nomination Web Page (Figure F-8) via the Nomination button under the
Station Category Function (also see Figure F-9).
A description of the menu entries (Figure F-8) used to implement the nomination func-
tion follows:
NOMINATION
CONTROL – In addition to the Time, this section of the Nomination
Web Page provides the following eight areas for nomination setup/selection:
Main function
The Main function selection is used to enable/disable the nomination function. If this
signal is set to the disable state, nomination will not occur.
Quantity units
The Quantity units selection is used to set the target units as MCF or MMBTU.
Control mode
Control mode provides for the selection of either the Valve Control or Flow Control
modes of nomination operation.
Status
The Status signal is an output of the nominations algorithm that indicates whether
there is currently a nominations period in progress. The user may change the state of
this signal to end an in progress nomination immediately, or to start the next period
immediately (see Manually Starting/Ending a Nomination Period).
Stop Mode
The Stop mode selection allows the user to automatically have the valve closed, i.e.,
shut-in on stop mode, or left in the last position upon reaching the target (or
programmed end period).
Daily Only Mode
When Daily mode is enabled, only the programmed start and end hours are used by the
ControlWave XFC; the Start/Stop days are ignored, i.e., nomination begins and ends
within a 24 hour period every day.