Emerson Vilter Vission 20/20, Operation And Service Manual

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18 – 1
Section 18 • Auxiliary Input / Output
Vission 20/20 • Operation and Service Manual • Emerson • 35391SC 2.7
Overview
The Auxiliary Input/Output (I/O) section of the Vission
20/20 gives the operator flexibility to add peripheral
instruments and/or devices such as motors, valves and
solenoids. With these additions, customer configurable
I/Os are useful to expand the functions of the Vission
20/20 where it was not explicitly designed to control.
Setting up one or more of the auxiliary inputs or out-
puts starts with the configuration screen. In order to
enable the auxiliary I/O, the Vission 20/20 must first
be equipped with one of the available expandable I/O
cards, and the card must be selected on page 6 of the
configuration screen. Once the appropriate card is avail -
able, then the operator will be permitted to enable and
name the desired auxiliary I/O. The operator can then
navigate to the Auxiliary I/O screen where the operation
of that I/O can be defined.
Digital Inputs
The Digital Inputs section of the auxiliary I/O allows an
operator to configure the auxiliary digital inputs, see
Figure 18-1. The digital input can be configured to pro
-
duce an alarm, a trip, and an inhibit on either a high or
low input. A low input is 0VAC and a high is 120VAC on
the enabled input. Leaving all options in their default
setting will mean no action will be taken on an enabled
input. The input will simply be available to view at the
panel or by communications.
Trip/Alarm Check:
• Selecting this checkbox enables the alarms and/or
trip functions of the Vission 20/20 for the desired
digital input. The accompanying drop-down box
gives the operator the flexibility to choose whether
the alarm and/or trip occurs if the input is high or low.
Inhibit Check:
• Selecting this checkbox enables the inhibit function
of the Vission 20/20 for the desired digital input. An
inhibit check prevents the compressor from start-
ing if there exists a condition where a trip will shut
down the compressor after it starts. The inhibit can
be selected to act on a high or low input and can be
selected to work with or without the alarm and trip
function.
Figure 18-1. Auxiliary I/O Screen - Digital Inputs (Page 1)