Honeywell UDC3500 - Algorithm Set up Group; Table 3-11 ALGORTHM Group Function Prompts

Configuration
78 UDC3500 Universal Digital Controller Product Manual 3/07
3.11 Algorithm Set Up Group
Introduction
This data deals with various control algorithms and Timer functions.
The Timer section allows you to configure a time-out period and to select the timer start
by either the keyboard (RUN/HOLD key) or Alarm 2. An optional digital input can also be
configured to the start the timer. The timer display is selectable as either “time
remaining” (see TI REM) or “elapsed time” (see E TIME).
Alarm 1 is activated at the end of the time-out period. When the timer is enabled, it has
exclusive control of the alarm 1 relay—any previous alarm 1 configuration is ignored. At
time-out, the timer is ready to be activated again by whatever action has been configured.
Function Prompts
Table 3-11 ALGORTHM Group Function Prompts
Function Prompt
Lower Display
Selections or
Range of Setting
Upper Display
Parameter
Definition
CONT ALG CONTROL ALGORITHM FOR LOOP 1—The
Control Algorithm lets you select the type of control
that is best for your process.
ON-OFF
ON/OFF—The simplest control type. The output can
be either ON (100 %) or OFF (0 %). The Process
Variable (PV) is compared with the setpoint (SP) to
determine the sign of the error (ERROR = PV–SP).
The ON/OFF algorithm operates on the sign of the
error signal.
In Direct Acting Control, when the error signal is
positive, the output is 100 %; and when the error
signal is negative, the output is 0 %. If the control
action is reverse, the opposite is true. An adjustable
overlap (Hysteresis Band) is provided between the
on and off states.
ATTENTION Other prompts affected: OUT HYST
DUPLEX ON/OFF—This is an extension of the ON-
OFF algorithm when the output is configured for a
Duplex control algorithm. It allows the operation of a
second ON/OFF output. There is a deadband
between the operating ranges of the two inputs and
an adjustable overlap (hysteresis) of the on and off
states of each output. Both Deadband and
Hysteresis are separately adjustable. With no relay
action the controller will read 50 %.
ATTENTION Other prompts affected: OUT HYST
and DEADBAND