Honeywell UDC3500 User Manual

Monitoring and Operating the Controller
3/07 UDC3500 Universal Digital Controller Product Manual 201
4.7 Control Modes
ATTENTION
After changing a Local Setpoint value, if no other key is pressed then takes a minimum of fifteen (15)
seconds elapsed time before the new value is stored in non-volatile memory. If controller power is
removed before this time, then the new setpoint value is lost and the previous setpoint value is used at
power-up. If, after changing the LSP value, another key is pressed, then the value is stored
immediately.
4.7.1 Mode Definitions
Table 4-5 Control Mode Definitions
Control Mode Definition
AUTOMATIC with
LOCAL
SETPOINT
In automatic local mode, the controller operates from the local setpoints and
automatically adjusts the output to maintain the PV at the desired value.
In this mode you can adjust the setpoint.
See Subsection
4.8 – Setpoints.
AUTOMATIC with
REMOTE
SETPOINT
In automatic remote mode, the controller operates from the setpoint measured at the
remote setpoint input. Adjustments are available to ratio this input and add a
constant bias before it is applied to the control equation.
See Subsection
3.15 Input 1 or 3.17 Input 2.
MANUAL
In the manual mode, the operator directly controls the controller output level. The
process variable and the percent output are displayed. The configured High and
Low Output Limits are disregarded and the operator can change the output value,
using the increment and decrement keys, to the limits allowed by the output type
(0 % to 100 % for a time proportioning output or –5 % to 105 % for a current output).
MANUAL
CASCADE
In the manual cascade mode, both control loops are in manual although there is still only one
output active. This mode is used to bring both loops into a reasonable operation area, at
which point the unit is placed into the automatic cascade mode.
If Loop 1 is placed in Manual control mode, then Loop 2, if in auto, is then placed in a pseudo-
manual mode thereby eliminating output bumps when Loop 1 is returned to Automatic control
mode.
AUTOMATIC
CASCADE
In Automatic cascade mode, there are two control loops, with one loop’s output acting as the
setpoint for the second control loop. There is only one physical output in this mode.

Honeywell UDC3500 Specifications

General

Brand	Honeywell
Model	UDC3500
Category	Controller
Language	English