Honeywell UDC2500 User Manual

Page 82

Configuration

UDC2500 Universal Digital Controller Product Manual

4/07

Function Prompt

Lower Display

Selection or Range of Setting

Upper Display

English

Numeric

Code

English

Numeric

Code

Parameter

Definition

DEV 4

DEVIATION (PROCESS VARIABLE
MINUS SETPOINT)—Represents –100 %
to +100 % of the selected PV span in
engineering units.

Zero deviation will produce a center scale
(12 mA or 50 %) output. A negative deviation
equal in magnitude to the Auxiliary Output
High Scaling Factor will produce a low end
output (4 mA or 0 %) output. A positive
deviation equal in magnitude to the Auxiliary
Output Low Scaling Factor will produce a
high end output (20 mA or 100 %).

FOR EXAMPLE:
Input 1 = Type T High Thermocouple
PV range = –300 °F to +700 °F
PV span = 1000 °F
Deviation Range = –1000 °F to +1000 °F
Auxiliary Output Low Scale Value = 0.0
Auxiliary Output High Scale Value = 1000

If PV = 500 °F and SP = 650 °F
then Deviation Display = –150 °F, which
is
–7.5% of the Deviation Range, so

Auxiliary Output = 50% – 7.5% = 42.5%

OUT 5

OUTPUT—Represents the displayed
controller output in percent (%). Cannot be
used with
Three Position Step Control.

SP 6

SETPOINT—Represents the value of the
setpoint currently in use and is shown in the
same units as those used by the PV.

LSP 1

LOCAL SETPOINT ONE—Auxiliary output
represents Local Setpoint 1 regardless of
active setpoint.

LSP 2

LOCAL SETPOINT TWO—Auxiliary output
represents Local Setpoint 2 regardless of
active setpoint.

0PCT 902 Value in

Engineering Units

AUXILIARY OUTPUT LOW SCALING
FACTOR— This is a value in engineering
units used to represent all AUX OUT
parameters except Output.

For Output, this is a value in percent and can
be any value between –5 % and +105 %.
However, keep in mind that relay output
types can only be scaled 0 % to 100 %.