Emerson Vission 20/20 Operation And Service Manual page 207

Appendix B • Vission 20/20 Application Procedures
Vessel Level Control Setup for 20/20
Panel
INTRODUCTION
This document provides guidelines to successfully setup
a vessel level control function in the Vilter 20/20 con-
trol panel. Vessel level control is achieved using a level
probe wired to an auxiliary analog input channel of the
20/20, thereby providing a 4-20ma signal proportional
to the vessel liquid level. Then based on the liquid level
setpoint entered into the 20/20, the analog output card
of the 20/20 will send a varying 4-20ma signal to a po-
sitioning valve, to open or close it to achieve a desired
level of liquid in the vessel.
ADDITIONAL VISSION 20/20 HARDWARE
An additional analog input card is required to sense the
4-20ma signal from the level probe.
Figure B-29. Selection of Installed Boards from Confi guration Screen
Vission 20/20 • Operation and Service Manual •Vilter/Emerson • 35391SC 2.0
An analog output card is required to output a 4-20ma
signal to the positioning valve, thereby increasing and
decreasing the amount of liquid being fed to the vessel.
If a level switch is installed in or on the vessel for an alarm
or trip function, then an additional digital input card will
be required as well.
SETUP
Step 1: Confi guration Screen Selection of
Installed Boards
Log on and navigate to the Confi guration screen, page
number 6, see Figure B-29. Insure that all boards that
are physically installed into the Vission 20/20 panel
have been selected or "checked". You should have ad-
ditional boards 8 and 10, and possibly board 4. Board
numbering starts from the left column, top to bottom
are boards 1 to 5. On the right column, top to bottom
are boards 6 to10.
(Confi guration Screen – Page 6)
B - 51