Setpoint Rate; Setpoint Ramp; Pv Hot Start; Run/Hold Key - Honeywell UDC3500 Product Manual

PV Hot Start

This is a standard feature. At power-up, the setpoint is set to the current PV value and the
Rate or Ramp or Program then starts from this value.

RUN/HOLD key

You can start or stop the Ramp or Program using the RUN/HOLD key.

4.28 Setpoint Rate

Introduction
When you have configured a SETPOINT RATE, it will apply immediately to local
setpoint change.
Configuration check
Make sure:
• SPRATE is enabled
• A Rate Up (EUHRUP) or Rate Down (EUHRDN) value has been configured in
Engineering units per hour.
ATTENTION
A value of 0 will imply an immediate change in setpoint, that is, NO RATE applies. See
Subsection 3.6 – Configuration group "SPRAMP" for details.)
Operation
When a change to local setpoint is made, this controller will ramp from the original
setpoint to the "target" setpoint at the rate specified.
The current setpoint value is shown as SPn XXXX on the lower display while the
"target" setpoint is shown as SP XXXX on the lower display.
Power outages
If power is lost before the "target" setpoint is reached, upon power recovery, the
controller powers up with Sn = Current PV value and it automatically "Restarts" from Sn
= current PV value up to the original "target" setpoint.

4.29 Setpoint Ramp

Introduction
When you have configured a SETPOINT RAMP, the ramp will occur between the
current local setpoint and a final local setpoint over a time interval of from 1 to 255
minutes. You can RUN or HOLD the ramp at any time.
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