MXS System Description and Installation Manual
UM06945
© Sagetech Avionics 2022 Proprietary Confidential
Page 46 of 56
7.10
Health Monitoring and Built-in-Test (BIT)
This section describes possible failure announcements by the transponder, events that trigger each failure
announcement, and processes to follow when those failures occur.
7.11
System Health and Status Overview
The MXS System health is monitored by reading the ACK message that the MXS will send to the flight
computer in response to any message received.
The System Fail monitors the required system inputs to the MXS. For proper operation, the following
inputs are required:
•
GPS Input (minimum 1 Hz frequency)
•
Valid ICAO Address
•
Supply Voltage (10-32 VDC)
The XPDR Fail monitors the health of the MXS unit itself. The BIT was designed to monitor the critical
circuit functions that are necessary for MXS operation. BIT failures will only be annunciated when in STBY,
On, or ALT mode.
Other information reported in the ack message is Mode Status (ON/OFF/STBY/ALT), Altitude Source
(Host/Internal), Altitude, and the states of the weight on wheels (WOW) and maintenance mode (MAINT)
discrete inputs.
