Honeywell MK VIII, MK XXII Egpwc Front Panel, Egpws Status Led’S, Audio Jack Mk V And Mk Vii Only

EGPWS LINE MAINTENANCE MANUAL

These tests primarily consist of more thorough hardware checks that would disrupt normal operation if continuously run.

2.3.4 EGPWC FRONT PANEL

To aid in troubleshooting the EGPWS, the front panel of the Warning Computer provides indicators and user interfaces as follows.

2.3.4.1 EGPWS STATUS LED’S

Three LED’s on the EGPWC front panel provide a high level indication of overall system status. These are:

•a yellow “External Fault” LED

•a green “Computer OK” LED

•a red “Computer Fail” LED

The yellow “External Fault” LED indicates that a fault external to the EGPWC exists. The green “Computer OK” LED indicates that the EGPWC is operating correctly with no internal faults. The red “Computer Fail” LED indicates that the EGPWC has an internal fault. Further explanation of internal and external faults is given in Section 3.4.1 and Section 3.4.2.

*Useful Tip #1 – The red Computer Fail LED illuminated does not guarantee the EGPWS is failed. It is possible for invalid strapping/wiring (MK V/VII only) to cause the LED to illuminate. Before returning a MK V/VII for repair, bench test the unit with power/ground applied, making sure to ground the parity pin. If the red Computer Fail LED does not illuminate during this bench test, the aircraft wiring is causing the Computer Fail condition.

2.3.4.2 FRONT PANEL SELF-TEST INTERFACE (MK V AND MK VII ONLY)

The EGPWC front panel provides a Self-Test switch for activating Self-Test features described in Section 2.3.5. This switch functions the same as cockpit Self-Test switches.

2.3.4.3 AUDIO JACK (MK V AND MK VII ONLY)

The EGPWC front panel provides a headphone jack for use during Self-Test. The audio jack is a standard 600Ω monophonic audio output compatible with a standard 2-connector ¼" audio plug headphones.

2.3.4.4 FRONT PANEL PCMCIA INTERFACE

For the MK V and MK VII, a PCMCIA card slot is provided in the front panel. For the MK VI, MK VIII, and MK XXII the PCMCIA interface utilizes an external PCMCIA interface called a “SmartCable” connected to the front panel Test Connector.

The PCMCIA interface provides a data downloading capability (either loading a new database from a PCMCIA Card or downloading history data from the EGPWC to a Fault History Card).

2.3.4.5 FRONT PANEL TEST CONNECTOR

The EGPWC front panel Test Connector provides communications support capabilities intended for maintenance and test functions. For the MK V and MK VII, this includes RS-232 and 422 communications. For the MK VI, MK VIII, and MK XXII this includes RS-232, power, and signals used for PCMCIA (SmartCable) operation. These serve as access to EGPWS signal monitoring, flight history, initiating BITE tests, updating databases, and other functions. The interface is full duplex and is intended for human interaction using custom interface programs such as the Honeywell WinVIEWS© utility (see Appendix A).

CAGE CODE: 97896 SCALE: NONE SIZE: A DWG NO.: 060-4199-180 REV: G SHEET 21 of 68