| 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.