Comtech EF Data C5 - Manual (Page 225)

Rev. 0 6-1 6-1
6
Chapter 6.
SYSTEM CHECKOUT
This chapter provides the following information:
! Satellite Terminal System Checkout
! Fault Isolation
! Module Replacement and Identification
6.1 Satellite Terminal System Checkout
CAUTION
This equipment contains parts and assemblies sensitive to damage by ESD.
Use ESD precautionary procedures when touching, removing, or inserting
PCBs.
The IDU comes equipped with an internal self-test feature. This feature is designed to
provide the operator with maximum confidence that the modem is operational without
installing external equipment.
A 2047 pattern is generated by the modem and routed through all sections. This is
accomplished by placing the modem in IF and baseband loopback. Pseudo Gaussian
noise is introduced to the modulated IF section allowing the modem to check its
indicated E
b
/N
0
against the known E
b
/N
0
of the demodulated input. Observe the
following:
! If this measurement falls outside of a specified window, the modem declares a
failed test.
! If an overhead card and/or Reed-Solomon card are installed, the signal is routed
through the card, verifying their operation.
! Faults, if any, are stored in the Stored Fault menu.