SYSTEM DESCRIPTION, INSTALLATION, AND MAINTENANCE MANUAL
MCS--4200/7200 Multi--Channel SATCOM System
23--20--35
15 Jul 2006
Honeywell International Inc. Do not copy without express permission of Honeywell.
Page 6--9
Table 6-2.
HPA Indicators/Controls
Indicator/Control
Description
PASS LED
Shows green after a test, if no failures are detected in the HPA
FAIL LED
Shows red after a test, if failures are detected in the HPA
PUSH--TO--TEST (PTT)
Push this button to start a test of the HPA
(c) HPA Front Panel LEDs
1
Functional testing effectively controls the on/off state of the front panel LEDs
during the period beginning with initiation of the functional testing
(POST/PAST), through execution of the functional test sequences (including
LED testing), and up to and including the indication of the test results on the
LEDs. Continuous monitoring exclusively controls the LEDs at all other
times.
2
The green LED (PASS) lights for 30
±
5 seconds at the conclusion of the
functional test sequences if both of the following are true:
•
The HPA determines there are no currently active CM failures having its
own Level I code (i.e., 04 or 07, as applicable)
•
No functional test failures have been detected with its own Level I code.
3
There must be no known failures in order to light the green LED as the
functional test indication.
4
The red LED (FAIL) lights continuously during the functional test indication
phase and through the transition to the CM indication phase, if the HPA
detects at least one currently active CM failure with its own Level I code. If
the HPA detects only functional test failures (i.e., no CM failures are
currently active), the red LED lights for 30
±
5 seconds and is then turned
off.
5
The red LED also lights as long as the failure persists, if the HPA detects
any CM failure that has its own Level I code while continuous monitoring is
controlling the LEDs. Otherwise, both LEDs are turned off. Continuous
monitoring itself never causes the green LED to light. The presence or
absence of functional test failures does not affect the CM indication.
(d) HPA-SDU Communication
1
The HPA communicates its functional testing/CM failure status to the SDU
through the HPA maintenance and status words. The HPA only indicates a
FW SSM state in its maintenance and status words, and active discrete
failure bits in its maintenance word. Since no failures unique to functional
testing activate the SSM FW state or the discrete failure bits in the
maintenance word, no functional test failures need to be latched until the
next functional testing sequence.
