Honeywell UDC3500 - Page 166

Configuration
150 UDC3500 Universal Digital Controller Product Manual 3/07
Function Prompt
Lower Display
Selections or
Range of Setting
Upper Display
Parameter
Definition
INPUT 3
INPUT 3—Same as Input 1
ATTENTION Do not configure Input 3 when Input 3
is used for Slidewire or Slidewire emulation.
INPUT 4
INPUT 4—Same as Input 1
INPUT 5
INPUT 5—Same as Input 1
CB OUT
CONTROL BLOCK OUTPUT—Output as calculated
by the control block (such as PID A). When using
one of the characterizers, OUTPUT is the output
value after it passes through the characterizer. CB
OUT is the control block output before it passes
through the characterizer.
ATTENTION CB OUT should not be used for Three
Position Step Control or Position Proportional
Control applications.
PV
PROCESS VARIABLE—Represents the value of
the Process Variable.
DEV
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 Output High Scaling Factor will
produce a low end output (4 mA or 0 %) output. A
positive deviation equal in magnitude to the Output
High Scaling Factor will produce a high end output
(20 mA or 100 %).
FOR EXAMPLE: Configuration is as follows:
Input 1 = Type T High Thermocouple
PV range = –300 °F to +700 °F
PV span = 1000 °F
Deviation Range = –1000 to +1000 °F = 2000 °F
Second Current Output Low Scale Value = 0.0
Second Current Output High Scale Value = 1000
CO Range = 4-20 mA
If PV = 500 °F and SP = 650 °F
then Deviation Display = –150 °F, which is
–150 / 2000 = –7.5% of the Deviation Range, so
Second Current Output = 50% – 7.5% = 42.5%
which is 0.425 X 16 mA + 4 mA = 10.8 mA