SAI ASOS/AWOS Display Interface Adapter:

Purpose: To sample AWOS data to monitor alarm naviagtional aid monitor status to provide control of rotating beacon in IFR conditions and to monitor for ELT alarms on 121.5 Mhz.

Part # SAI-IF1

This unit, housed in a metal enclosure 6.25” x 7.25” x 2.75” has the ability to house three circuit boards.

Board #1 , the RS-232 /RS-485/RS-422 interface tap will provide for a transparent data tap of the AWOS weather information. It then provides for a local RS-232 drop as well as a RS-422 drop for extended displays up to 4000 feet away.

Board #2 , the SAI Alarm Board, will monitor up to four dry contacts for alarm status monitoring and will also output to two relays. One relay is dedicated to IFR alert for turning on the airport rotating beacon. The other relay is user defined in the setup menu.

The four alarm status inputs are sampled by the SAI software once every 30 seconds and will upload the status of them to the internet once every sixty seconds. Date and time stamps for the change in levels will be seen and recorded.

Board #3, the SAI ELT Alarm Receiver, is an anti falsing 121.50 MHz receiver with digital timer output to prevent false ELT alarms. A constant alarm signal of either 5 minutes or 10 minutes must be present to trigger the alarm. As soon as the alarm is no longer received, the unit will self reset. The SAI software will monitor this alert signal line once every 30 seconds and will upload to the internet the alarm status every sixty seconds. Date and time stamps for the change in levels will be seen and recorded.