Apr/2006 - Honeywell KHF 1050 System Installation Manual

• The KRX 1053 Receiver/Exciter sets the SDI field of all ARINC 429
transmitted messages to 00B, and it sets bits 30 and 31 (status field) of
all messages except that with label 351 to 11B, indicating an invalid
condition shall set bits 30 and 31 (status field) of the label 351
Maintenance Status message to 00B, indicating a fault condition. It is
intended that at least one of these discrete inputs, but not both, be
asserted.
The KRX 1053 Receiver/Exciter processor samples the state of these
discrete inputs only at initial power application. The state of these discretes
are assumed to not change during operation.
5.D.(1)(e) Narrow/Wide Freq Range - (J10531-100) NAR/W FREQ RNG
When the NARROW/WIDE FREQ RANGE discrete input is asserted
(grounded), the KRX 1053 Receiver/Exciter restricts operations to the
frequency range from 2.0000 MHz through 22.9999 MHz, and clears bit 18
of the Receiver/Exciter Output Label 037, Word ID #1 (Control Status) word
to logic 0.
When the NARROW/WIDE FREQ RANGE discrete input is not asserted,
the KRX 1053 Receiver/Exciter operates over the full frequency range from
2.0000 MHz through 29.9999 MHz.
If the NARROW/WIDE FREQ RANGE discrete input is asserted and the HF
controller commands a transmit or receive frequency above 22.9999 MHz,
the receiver/exciter will go to 22.999 MHz.
The KRX 1053 Receiver/Exciter processor samples the state of this discrete
input only at initial power application. The state of this discrete is assumed
not to change during operation.
5.D.(1)(f) Stuck MIC Protection- (J10531-36) STUCK MIC PTCT
When the STUCK MIC PROTECTION discrete input is asserted
(grounded), the receiver/exciter stops transmitting after a transmission
duration equal to a constant set in non-volatile memory during
manufacturing test or service center test.
• This time duration can be set to a value between 30 seconds and 240
seconds. The default time is 120 seconds.
• The KRX 1053 Receiver/Exciter processor samples the state of this
discrete input only at initial power application. The state of this discrete
is assumed to not change during operation.
Revison 2
N
KHF 1050 SYSTEM INSTALLATION MANUAL
23-10-09
Page 2035

Apr/2006