Specifications
1-Wire Indoor Sensor/Interface Kit

Primary Interface Dallas Semiconductor/Maxim 1-Wire®
RS-232 Interface DB9-F connects to PC COM port with a standard serial cable.
Indoor Temperature Sensor Device: Dallas Semiconductor/Maxim DS18S20
Range: -67° F to +257° F
Accuracy: ±0.5° C from -10° C to +85° C
Pressure Transducer/Circuitry Sensor: Motorola MPX4115AP
Sensor Accuracy: ±1.5% 0° to 85° C.
Range: any 200 mb range, typically 870 mb ~ 1070 mb
Response Time: 1 mS
Circuit: Instrumentation Amplifier followed by single ended stage to give required gain. IA uses 0.1% precision resistors and the final stage w/1.0% resistors to insure gain balance and stability.
Power 14-18 VDC, less than 50 mA
EMP Sensor Interface Electrically isolated. Designed to interface with the Stormwise EMP sensor model LSU-30. Can respond to pulse widths down to 1 mS. Expected R-on of the darlington pair in the sensor to be approximately 100 ohms.
Rain Gauge Interface* Electrically isolated. Configurable to work with any reed switch type gauge that closes a circuit when 0.01” is accumulated. Configurable jumpers allow interfacing to a variety of gauges.
Background Radiation Monitor Interface* Electrically isolated. Configurable to work with the Aware Electronics RM-60/RM-70 background radiation monitors.
Control Interfaces Open drain using VN10KN3 V-MOSFET. Drain current rated at 310 mA continuous. These interfaces are used to control aspirator power and/or a rain gauge heater. However, since they are software controlled, they could be used to control any other devices with the appropriate program.
iButton Clip The clip allows installation and use of any of the iButton 1-Wire products available from Maxim. Specifically, this was added to allow the DS1994 Real-Time Clock iButton to be used with the T-238/T-238+ with the appropriate firmware revision.

* The unit is shipped with the necessary parts to implement the rain gauge interface. If you plan on using a background radiation monitor and still wish to have a rain gauge interface, the outdoor unit, the X1W-2, must be purchased. The rain gauge would then be installed on the outside unit and additional parts populated on the X1W-1 board. See the section on the background radiation monitor option for more details.