Installation Manual

THALES Communications
OIM
AHV1600-SYSTEM
Page 116
July 16/09
32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15
14
13 12 11 10 9 8 7 6 5 4 3 2 1
Parity
SM
MSB
Height data value in BCD format
LSB
SDI
LSB
Label « 165 »
MSB
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 0 1 0 1 1 1 0
Figure 115 – ORGANIZATION OF HEIGHT DATA WORD LABEL “165"
(3) DISCRETE INPUT SIGNAL
(a) Discrete input signal “FCT_TST”
The AHV1600 transceiver receives the discrete input signal “FCT_TST” from the navigation
and guidance systems to activate its “Built In Test (BIT)” function.
The “FCT_TST” discrete input signal shall initiate the following function of the AHV1600
transceiver:

Built In Test function initiated when it is set to low level voltage (discrete grounded).
 Built In Test function not initiated when it is set to high level voltage (discrete open).
To initiate the internal Built In Test function of the AHV1600 transceiver, the minimum time
duration of “FCT_TST” discrete input signal shall be 200ms when measured at 50% level of
the electrical changing voltage.
In the AHV1600 transceiver, the “FCT_TST” discrete input signal shall be in accordance with
the following electrical characteristics:
 Low level voltage  + 3.5 VDC with sink current < 2mA (discrete grounded).
 High level voltage  +15.3 VDC with sink current < 1 mA.
 Maximum level voltage  +32.2 VDC.
when measured to the “M_GND” reference signal.
In the AHV1600 transceiver, the discrete input signal ”FCT_TST” shall be protected against
the indirect effect of lightning.
(b) Discrete input signal “TST_INH”
The AHV1600 transceiver receives the discrete input signal “TST_INH” from the navigation
and guidance systems to inhibit its “Built In Test (BIT)” function.
The “TST_INH” discrete input signal shall inhibit the following function of the AHV1600 trans-
ceiver: