Specifications

8
The RS 485 portion of the Comm Port will only be active if the
Controller is fitted with the COMMS option (see section 1.2.1
LEVL C). The COMMS option allows the microprocessor to
communicate with a PC running the CALCOMMS software.
RS 485 Wiring Connections
Tx/Rx+ = Pin 7
Tx/Rx- = Pin 2
Ground = Pin 4
If runnng the CALCOMM computer program, see the
“CALCOMM” section of this manual for set-up instructions.
2. Analog Voltage Output
The Analog Voltage Output is always active. Temperatures of 0-
100°C (32-212°F) correspond to an output of 0-1VDC. Relative
Humidity of 0-100% RH also corresponds to an output of 0-
1VDC. The analog outputs are a direct voltage reading from the
sensors.
This connector is configured as an Analog Voltage (0-1VDC)
Output for monitoring the temperature and/or humidity levels
using a chart recorder or other analog input recording device.
Minimum acceptable input impedance for the analog recording
device is 20k Ohms. An input impedance lower than 20k Ohms
will load down the output signal and will affect the measurement
and control accuracy of the entire system. An A/D converter
can be used to convert the signal for use with a data logger or
computer.
Analog Voltage Output Wiring Connections
Temperature Positive (+) = Pin 9
RH Positive (+) = Pin 1
Common (Temp & RH) Ground (-) = Pin 4
1.1.2.3 DEHUMIDIFY IN/OUT
The Model 561 Desiccant/Pump Dehumidification System uses a pair of
quick disconnect fittings. The pump is mounted inside the Chamber
control cavity and the desiccant column is placed external to the chamber
in a location determined by the user. These two fittings (Air In and Air Out)
connect the column into the dehumidify loop. (See Section 2.2.1 Model
561 Dehumidification System)