December 1, 2004 - 16 -
SWACOM TRAINING GUIDE
-Software loading PCMCIA card slot (Personal Computer Memory Card International Association) -Portable data loader (PDL) connector
Maintenance Tip
A functional self-test is performed upon initial application of primary power to the CMU or by activation of the PUSH-TO-TEST button. During the self-test the PASS and FAIL LED’s alternately blink at a 1 hz rate while individual tests are performed. Upon completion of the self-test, the PASS FAIL LED’s continue blinking in tandem for 3 seconds at a 2 hz rate.
At the end of the self-test (after 3-second 2 Hz blinking) the operational state of the CMU will be indicated by the following:
-A solid ILLUMINATION of the PASS LED when no faults are
seen
-A solid ILLUMINATION of the PASS LED with the FAIL LED blinking at a 0.5 Hz rate when a noncritical fault occurred, but the CMU remains operational
-A solid ILLUMINATION of the FAIL LED when a critical fault occurred where the CMU is unable to enter an operational state.
For more specific fault information, access the Maintenance Menu and Fault Log through the MCDU.
23-27
SOUTHWEST AIRLINES PROPRIETARY(c) All rights reserved
SOUTHWEST AIRLINES.
SWACOM TRAINING GUIDE
PDL CONNECTOR
SELF TEST INDICATORS
SELF TEST BUTTON
SOFTWARE LOADING PCMCIA CARD SLOT
23-27-AC-007
ACARS -COMMUNICATIONS MANAGEMENT UNIT
December 1, 2004
23-27
- 17 -
SOUTHWEST AIRLINES PROPRIETARY(c) All rights reserved
SOUTHWEST AIRLINES.
ACARS - COMMUNICATIONS MANAGEMENT UNIT Purpose
The Communication management unit (CMU) receives the uplink data and controls the transmission of downlink data to and from the VHF transceiver number 3.
General
The CMU does these tasks:
-Monitors input signals
-Formats downlink messages
-Monitors downlink data to make sure it is correct
-Monitors uplink messages to make sure they are correct
-Decodes uplink messages
-Controls the mode of operation
-Controls data transmission
-Gives acknowledged/not acknowledged response
-Tunes and controls a VHF radio number 3
-Monitors system operation.
The CMU processes only uplink messages that come with the airplane registration code. This same code also goes on all downlink messages to identify the airplane.
Description
The following indicators and controls are located on the front of the CMU:
-PASS indicator (LED)
-FAIL indicator (LED)
-PUSH TO TEST button
December 1, 2004 - 16 -
SWACOM TRAINING GUIDE
-Software loading PCMCIA card slot (Personal Computer Memory Card International Association) -Portable data loader (PDL) connector
Maintenance Tip
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本文鏈接地址：Maintenance Training SWACOM TRAINING GUIDE 機務培訓手冊 SWACOM培訓指南(13)
