Honeywell UMC800 Reference Guide

Function Blocks
3/99 Function Block Reference Guide 159
2.51 PT Function Block
Description
The
PT
label stands for
Periodic Timer
. This block is part of the
Counters/Timers
category. It looks like
this graphically on the Control Builder.
Function (1 or 2)
1. Time/Cycle:
Generates a discrete output pulse at a specified start time based on the real-time clock and
at specified time periods thereafter.
Start Times = Month, Day, Hour, Minute, Second
Cycle Periods = Monthly, Weekly, Daily
Time Cycle Periods Within a Day = Hours (0-23) Minutes (0-59) Seconds (0-59)
Note: Once started, period repeats until reset.
2. Reset Cycle:
Generates a digital output based on a digital input and at regular intervals thereafter.
Time Start = ON to OFF transition of reset input.
Cycle Time Period = Hours (0-23) Minutes (0-59) Seconds (0-59)
Input
RST = Reset/Enable (ON = Output disable, OFF = Output enable)
Output
OUT = Logic State. Output turns ON for one scan cycle when elapsed time matches setpoint time (One-
shot)
Block Properties
Double click on the function block to access the
function block properties dialog box.
Block Order (Read Only)
You can change the assigned execution order
number by selecting “Execution Order” in the
“Configure” menu and arrange the order to suit
your control strategy.
Configuration Parameters
You must configure the PT function block
parameters to the desired value or selection that
matches your operating requirements.
Table 2-45
describes the parameters and the
value or selection.

Honeywell UMC800 Specifications

General

Brand	Honeywell
Model	UMC800
Category	Controller
Language	English