User Manual

OPERATION AND INSTALLATION MANUAL
KVJEVR718
Enhanced VHF Radio
EVR716
23-11-02
Page 40-2
2000/02/15
(2) Default Mode
At power up, the default mode is mode 0A, tuned to the fast tuned frequency (before
switching off).
NOTE: In less than one second, the aircraft control provides the ARINC 429 word
indicating the active frequency use.
(3) Change of Mode
Possible modes are ARINC 716 VOICE (0A or 0B modes) and ARINC 716 data
(mode 1A).
The selection is determined by:
− the Voice/Data discrete ("V" :open state; "D" : grounded state),
− the content of the ARINC 429 DFS bus label word,
− the activity of the ARINC 429 bus (C)MU ("active" if the EVR716 transceiver
receives the 270 label every second),
− the content of the label 270 word which determines if one (C)MU can be declared
primary.
C. Maintenance States
Two maintenance states are to be considered:
(1) On-Line Maintenance (Aircraft Grounded)
In this state, the EVR716 transceiver is in the same environment as in its operational
state. This state is activated either by power up or by tests initiated by a pushbutton
(TEST) on the front panel (see figure 10-1).
During the tests, the equipment is not operational. Initiated tests are also allowed by
maintenance software control.
The result of the test is displayed on six LEDs on the front panel (see figure 10-3),
saved on the NVM (Non Volatile Memory).
(2) Off-Line Maintenance
In this state, the EVR716 transceiver is not in its operational system environment but
in a technical environment (test bench, maintenance workshop, etc.). The activation of
this state is possible only when pins TP5A and MP14B are grounded. This state allows
the downloading of the functional and maintenance software. The tests provided in
this state allow an investigation at the SRU level.
The result of the tests is displayed on six LEDs on the front panel and five LEDs
located on the DPU (Digital Processing Unit) module indicating a failure code (SRU
level).