Emerson Process Management ControlWave EFM 3808 User Manual

Page 209

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CI-ControlWave EFM

Appendix F / F-

9

arrive at the target (volume or energy) as quickly as possible without regard to the
programmed end time.

Flow Control
The Flow Control method internally enables the PID flow control algorithm in order to hit
the target volume/energy at exactly the programmed end time.


The user programs the ControlWave EFM t(via the ‘Stop Mode’ button) to either close the
valve upon reaching the target or leave it in its last position.

F.5.4.1 Nomination Operation


See sections F.5.4.1.1 through F.5.4.1.5.

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 EFM. 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 EFM will automatically disable nomination.
When properly configured the ControlWave EFM 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 (see Figure F-5 or 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

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