Philips SPENDEX 40 Maintenance Manual page 46

■
■
r
-
I
NATO CONFIDENTIAL
S P E N D E X 4 0 U A 8 2 5 1 / 0 0 A N D / O l L I M I T E D M A I N T E N A N C E M A N U A L
this the equipment can no longer be used in both the secure and the
nonsecure mode, and in a non-fatal alarm when the equipment can still
only be used in the nonsecure mode.
A fatal hardware alarm results in unconditional changeover to the
alarm state. An alarm appears in the display, the self-test stops,
the LED starts to flash and an alarm signal becomes audible.
A non-fatal hardware alarm results in a display report of some
seconds. After that the self-test will be continued. When further no
f a t a l h a r d w a r e e r r o r s a r e d e t e c t e d , fi n a l l y " * " a p p e a r s i n t h e
display and it will only be possible to use the apparatus for
nonsecure communication.
During the self-test also the internal or external modem will be
tested. Which modem will be tested depends on the Low/High Frequency
setting. If the equipment is set on Low Frequency (LF), the internal
modem will be automatically tested. Is it set on High Frequency (HF),
the external modem will be tested.
For a successful course of the test of the internal modem the
2-wire/4-wire and the Half/Full Duplex settings are important.
Equipment type UA 8251/01 should be set on 2-wire Full Duplex (2WFD).
With equipment type UA 8251/00 all setting possibilities are allowed,
except 2-wire Full Duplex.
On the basis of the following fault finding tables the cause of a
hardware alarm detected during the self-test can be located. First
try to stop the alarm by switching off the equipment and then
switching it on again.
9 9 2 2 1 5 4 1 3 4 3 1 6 - 2
NATO CONFIDENTIAL