Honeywell HC900 Reference Guide

Function Blocks
UPDN Up/Down Function Block
426 HC900 Hybrid Control Designer Function Block Reference Guide Revision 11
2/07
UPDN Up/Down Function Block
Description
The UPDN label stands for UP/DOWN Counter.
This block is part of the
Counters/Timers category.
Function
The output counts the number of rising edge logic transactions on the input to the block up to a preset value
(RPRE or LPRE). When the preset value is reached, a logic output (PREI) is enabled until a Reset input
(RST) resets the block.
Value may be set to increase to the preset value or decrease from the preset value.
Inputs
^X
= Positive Edge Detect Count Input
RPRE = Remote Preset
RST = ON resets the count
CNTDN = ON counts down
Outputs
OUT
= Output
PREI = Preset Indicator
Block properties
Double click on the function block to access the function block properties dialog box.

Honeywell HC900 Specifications

General

Series	HC900
Redundancy	Optional
Programming Language	Function Block Diagram, Ladder Logic, Structured Text
Inputs	Analog, Digital
Outputs	Analog, Digital, Relay
Display	Optional
Control	PID, Advanced Control
Power Supply	24V DC or 100-240V AC
Storage Temperature	-40°C to 85°C
Humidity	5% to 95% non-condensing
Communication Protocols	Modbus, Ethernet