Input Attenuator; Tx Gain Monitoring - Honeywell ASPIRE-400 System Description, Installation And Maintenance Manual

SYSTEM DESCRIPTION, INSTALLATION, AND MAINTENANCE MANUAL
(5) The HPA echos the existing condition of "PA Control" of the most recent ARINC-429 label
143 HPA Command word in the ARINC-429 label 143 HPA Status word of the current
reporting interval when known else default with "Carrier Off" until assigned otherwise.
(6) While in Normal Operating mode, the HPA achieves full transmit capability within 50 ms
of the PA function being enabled. This may occur from commanded capability if no
inhibitions prevent it or upon primary power restoration from primary power interrupt if
primary power inhibition was the cause of PA deactivation. Allocation accounts for Power
Amplifier sequencing to enable drain voltage.
(7) If the PA function is enabled, the HPA achieves its PA function disable state within 50ms
of receipt of the ARINC-429 HPA Command word whose state of indication of "PA
Control" is "Carrier Off". Allocation accounts for Power Amplifier sequencing to disable
drain voltage.
(8) Any transition of the PA function between enabled and disabled states should be
recorded to the Event Record log.
B.

Input Attenuator

(1) The HPA provides a minimum of 20 dB of input attenuator monotonic adjustment in
increments of nominally 1.0 dB.
(2) The design has a persistent means of defining the input attenuators maximum
adjustment capability implemented in the design in that is readable by software.
Persistent means by hardware or manufacturer reserved memory that cannot be
overwritten by application reload. The software reported "PA Backoff Range" is "Input
Attenuator Maximum Attenuation Capability" - 16 computed in dBs and expressed in 4-
bits. The reportable attenuator maximum attenuation capability is therefore limited to a
range of 16(0000) to 31(1111).
(3) The state of indication of "PA Backoff Range" to be reported in ARINC-429 label 143 HPA
Status word is the declaration of the input attenuator's maximum adjustment capability
implemented in the design.
(4) The cumulative attenuation accuracy should be less than or equal to ±2.0 dB over
temperature and frequency.
(5) Software derives the commanded attenuation value from the "PA Backoff" declared in
ARINC-429 label 143 HPA Command Word during Normal Operation to set the input
attenuator setting except in circumstances of Power Amplifier Management override
during the transition period of Power Amplifier Activation/Deactivation.
(6) Any change to the value of "PA Backoff" as declared in ARINC-429 label 143 HPA
Command word during Normal Operation state should be recorded in a change of
backoff event in the Event Record log.
C.

Tx Gain Monitoring

(1) The input detector function and output detector functions are synchronously sampled
(2) The input and output power detectors are used to compute:
(a)
(b)
(c)
(d)
EFFECTIVITY
ALL
© Honeywell International Inc. Do not copy without express permission of Honeywell.
ASPIRE-400
"Input Level" reported in ARINC-429 label 357 Aero Power word
"RF Power Input" status reported in ARINC-429 label 350 HPA Maintenance
word
"Output Level" reported in ARINC-429 label 357 Aero Power word
"Relative Power" reported in ARINC-429 label 143 HPA Status word
23-15-49
3rd rvw Draft as of:
29 January, 2020
Page 2-11
22 Apr 2019