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HumiTherm Ultra
User Manual
APPENDIX - F
DIGITAL INPUTS & OUTPUTS
DIGITAL INPUTS
The microPLC Control Unit incorporates interfaces for potential-free digital inputs for various functions described below.
Power Fail
This Digital Input is used if provision is made for running the controller on an auxiliary power sources like battery or inverter and
a Switch is mounted for detecting main power source failure. This input detects whether the controller is being powered from
Main or Auxiliary power source.
Door Open
This Digital Input is used to warn if the ch mber door is left open for more than a user programmed time period by activating the
a
Alarm. Also a record is generated each time the door is opened or closed.
Water Level
This Digital Input can be used to detect Low Water Level in the Steam generating boiler by mounting a Float / Water Level
Switch. pon det cting Low Water Level, the boiler supply is cut-off and Alarm is
U
e
activated for safety.
Thermostat
This Digital Input can be connected to a thermostat to detect Low Water Level to change over from Main Control Gadget Set to
Standby Control Gadget Set and vice-a-versa. The Thermostat used is set to 110 °C and is immersed in boiler water. So long
as the water level is normal, the thermostat remains immersed and the temperature is below 100 °C. Under Low Water Level
condition, the thermostat gets exposed to air and the temperature eventually rises above 110 °C and the thermostat trips.
Alarm Acknowledge
This Digital Input can be used to mute the larm utput elay.
A
O
R
DIGITAL OUTPUTS
The microPLC Control Unit provides several digital outputs for Alarm & Process Control. The outputs are voltage levels rated
12 VDC @ 40 mA each.
Heater
This Digital Output switches in accordance with the output power computed by PID loop controlling the Temperature. The
output drives the heating element through external Relay / SSR.
Humidifier
This Digital Output switches in accordance with the output power computed by PID loop controlling the %RH. The output
drives the boiler heater through external Relay / SSR.
Compressor
This Digital Output switches in accordance with the On-Off Strategy & Time-Delay set for the compressor operation for cooling
/ de-humidification. The output drives the power to compressor through external Relay / SSR.
