User's Guide

DRAFT
Page 3-10
17 Mar 2016
23-15-87
© Honeywell International Inc. Do not copy without express permission of Honeywell.
SYSTEM DESCRIPTION, INSTALLATION, AND MAINTENANCE MANUAL
ARINC 781-500 SDU and SCM
(1) PIM Test Overall Status
At the end of the PIM test, the A781-500 SDU displays the test results on the TCP screen.
The TCP displays the overall PIM status and results for each direction. If the overall status is
PASS, the SDU can continue to use SBB services.
If the overall status is FAIL:
• Check the cable connections of the antenna and the SDU.
• Check the direction in which the test failed and verify that the antenna is not blocked in
that direction. Refer to "Directional PIM Test Results" on page 3-10.
(2) Directional PIM Test Results
The SDU performs the PIM test with the antenna pointing in different directions and displays
the results of the test in each direction. If the overall status of the PIM test is FAIL, you can
check the specific directions in which the test failed.
For each direction, the PIM test results provide:
• Overall Status—pass or fail
• The direction coordinates
• The signal degradation—pass level is adjustable in Secure ORT
• Possible interference—interference caused by environmental factors, not the SDU
transmit frequencies. Interference indicates that the SDU received a signal in the receive
band even when it wasn’t transmitting, therefore an external signal may be interfering
with communication in that direction
• Signal and noise levels before and after the test—the SDU uses this information to check
for possible interference.
SAFE MODE Configuration error detected.
Possible causes:
• Strapping parity error.
• FMPA messages when
standalone mode strapped.
• Secure ORT parameters are not
available.
SATCOM cannot operate until
configuration fault is eliminated (see
description for possible causes).
Once the fault is eliminated, wait for
the status to change to READY and
run PIMBIT.
NOT ALLOWED IN AIR Air/Ground status indicates in air.
PIMBIT cannot be performed while
the aircraft is in the air.
Run PIMBIT when the aircraft is on
the ground.
Table 3-4. PIM Test Conditions
Test Status Description Action
DRAFT as of
4 Mar 2016