Honeywell HC900 - DEWP Function Block

Function Blocks
DEWP Function Block
Revision 11 HC900 Hybrid Control Designer Function Block Reference Guide 133
2/07
DEWP Function Block
Description
The DEWP label stands for Dewpoint Calculation.
This block is part of the
Calculations category.
Function
Monitors Dewpoint or Carbon Potential, or uses a Zirconia Probe sensor input to supply a Dewpoint PV to
a PID function block for Dewpoint control. Use in conjunction with other blocks including a PID to
generate more elaborate control strategies than that provided by the Carbon potential (CARB) function
block.
Inputs
Probe
= Oxygen Sensor Input from AI (0-2 mV)
TEMP = Temperature Input (°F or °C) from AI Input
%CO = Percent Carbon Monoxide Input 1 - 100 %
Outputs
DEWPT
= Calculated Dewpoint Output
%C = Calculated Percent Carbon Output
SPHLIM = Control Setpoint High Limit for Anti-soot.
WRLIM = Command to write the setpoint high limit.
LOTEMP = ON when TEMP is <= calculated low temperature dropoff.