Users Manual
ALL
EFFECTIVITY
© Honeywell International Inc. Do not copy without express permission of Honeywell.
Page 2-25
22 Apr 2019
23-15-49
SYSTEM DESCRIPTION, INSTALLATION, AND MAINTENANCE MANUAL
ASPIRE-400
(d) The SDU enters Standby state on start-up and stays in Standby state until
commanded to go into Active State via Label 272 from the TCP when the
following is true:
1 ORTconfigured for Aircraft Directed Dual Safety SATCOM.
(e) When all the following are true:
1 ORTconfigured for Aircraft Directed Dual Safety SATCOM.
2 SSM of Label 272 is set to NO on the selected ARINC 429 MCDU
interface for at least 3 consecutives labels.
3 Bits 12-11 (Operational Mode Command) is 01b (SDU1 Active & SDU2
Standby) in Label 272 Operational Mode Command Word that is being
used.
(f) The ACD sets the "ACDir Select Mode" to:
1 SDU1 Else
2 SDU2 (Operational Mode Command is set to 10b - SDU2 Active & SDU1
Standby).
NOTE: The priority is to use Label 272 from MCDU 1 when valid,
then MCDU 2 when Label 272 is missing/invalid from MCDU
1, then MCDU 3 when Label 272 is missing/invalid from both
MCDU 1 & 2.
(g) The ACD keeps the "ACDir Select Mode" unaltered when all the following are
true:
1 SSM of Label 272 is set to FT.
2 Bits 12-11 (Operational Mode Command) is 01b (SDU1 Active & SDU2
Standby) or 10b (SDU2 Active & SDU1 Standby) in Label 272
Operational Mode Command Word that is being used.
NOTE: The priority is to use Label 272 from MCDU 1 when valid,
then MCDU 2 when Label 272 is missing/invalid from MCDU
1, then MCDU 3 when Label 272 is missing/invalid from both
MCDU 1 & 2.
(h) The SDU transitions to Active State, else Standby State, when all the following
are true:
1 ORTconfigured for Aircraft Directed Dual Safety SATCOM.
2 The SDU number (per the strapping) is the same as "ACDir Select
Mode".
3 The DSD is not asserted.
(i) Bits 11, 12 and 13 of CFDS Label 362 OCA Fault Summary Word are all set to
unavailable (1) when all the following are true:
1 ORTconfigured for Aircraft Directed Dual Safety SATCOM.
2 The SDU is in Active mode.
(j) That SDU transitions to Standby state when the ORT configured for Aircraft
Directed Dual Safety SATCOM.
(k) On entering Active mode, the ACD:
DRAFT
3rd rvw Draft as of:
29 January, 2020