Honeywell HC900 Reference Guide

Function Blocks
RH Relative Humidity Function Block
320 HC900 Hybrid Control Designer Function Block Reference Guide Revision 11
2/07
RH Relative Humidity Function Block
Description
The RH label stands for Relative Humidity.
This block is part of the
Calculations category.
Function
Calculates RH as a function of wet bulb temperature, dry bulb temperature and atmospheric pressure.
0-100 % RH is output as a floating point number between 0 and 100.
Input
DRY
= Dry Bulb Temperature (°F, metric = °C)
WET = Wet Bulb Temperature (°F, metric = °C)
PRES = Atmospheric Pressure (psi, metric = Pa)
Output
RH
= Relative Humidity (0-100)
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