The 420 Quad sensor module extends the capability of the GTX   by interfacing with up to four sensors.  These snesors may have counter type output such as some types of wind sensors ot analog outputs such as potentiometers or thermistors.  Two of the n alog inouts may  be configured as differentila inputs.  The picture below shows a Quad 420 MSM at a Weather Station. The 420 is used to read a wind sensor speed and direction, air temperature, and relative humidity.

Addtionally the 420 may be used external to the main enclusure.  This allows a distributed system to constructed where a number of Modules may be used at the site.  Three SDI-12 wirng ports allow  only a single cable to be used on structures such as towers or dams.
Power is derived from the SDI-12 port.  Power consumption for most system set up is less than 1 milliwatt.

Options:
Package:       ABS plastic Enclosure        
Aluminimum NEMA enclosure
Packing gland cable entry
MS type connector cable entry
ADC : 12 bit or 16 bit