-
The opposite FMGC (FD COND logic).

 1EFF : ALL 1 22-11-00Page 1 1 1 Feb 01/98 1 1 1CES 1

 FD Engagement
 Figure 001
 1EFF :  ALL  1  22-11-00 Page 2 
1  1  Feb 01/98
 1  1
 1CES  1

 FD - Engage Hardware Logic
 Figure 002

 1EFF : ALL 1 22-11-00Page 3/4 1 1 Feb 01/98 1 1 1CES
1 (a) FLIGHT GUIDANCE HEALTHY logic (FG HLTY) (Ref. Fig. 003)

 1_ FG HLTY logic on command side
 This signal which is consolidated by an FG HLTY signal from
 the monitoring channel is generated by the following
 monitoring functions:

 a Internal monitoring of the guidance
_ This monitoring function comprises the result of the safety tests. These tests are initiated on the ground at power rise (long cutoff) The devices to be tested are : the memories, the watchdog, the power supply monitoring circuit, etc.
 -
Monitoring of the +5V, +15V and -15V powers (supplied from the aircraft 28 VDC) This is a cross - monitoring between CMD and MON channels (the CMD side monitors the MON powers and vice versa)

 -
Monitoring of the access to the INNER/GUIDANCE common memory

 -
Monitoring of the ARINC input and output sequencers

 -
Monitoring of the monitor ARINC transmissions

 -
Monitoring of the real-time monitor of the inner loop processor

 -
Monitoring of the alpha-floor logic.

 b Internal monitoring of the inner loop CPU
_ This monitoring function comprises:
 -
Monitoring of the ARINC input and output sequencers

 -
Monitoring of the AP output orders

 -
Monitoring of the INNER/GUIDANCE common memory

 -monitoring of monitor ARINC transmissions.
 c Monitoring of the exceptions of the guidance CPU
_ An exception results from an instruction which cannot be performed normally for these reasons:
 -Either it does not follow the rules of the memory protection
 -
Or it leads to an erratic result

 -
Or the instruction itself is garbled.

 d Monitoring of the exceptions of the inner loop CPU
_
 e Guidance processor watchdog output
_
 1EFF : ALL 1 22-11-00Page 5 1 1 Feb 01/98 1 1 1CES 1

 FG HLTY Logic
 Figure 003
 1EFF :  ALL  1  22-11-00 Page 6 
1  1  Feb 01/98
 1  1
 1CES  1

 2 FG HLTY logic on monitoring side
_ This signal which is also consolidated by the FG HLTY signal from the command channel is generated by the following monitoring functions:
 a Software monitoring of the monitor CPU
_
 This monitoring function comprises:

 -Result of the safety tests
 -
Monitoring of the +5V, +15V and -15V powers of the command channel

 -
Monitoring of the ARINC input and output sequencers

 -
Monitoring of the command ARINC transmissions

 -
Monitoring of the AP orders

 -
Monitoring of the FD orders

 -
Monitoring of the alpha-floor logic.

 b Monitoring of the exceptions of the monitor CPU
_
 c Watchdog activation
_
 (b) FD ENGAGED logic (FD ENGD) Three conditions are required to obtain FD ENGD
 1 FD specific conditions (FD COND)
_ (Ref. Fig. 004) This logic takes into account the actions on the FD pushbutton switches on the FCU (Ref. Fig. 003)
 NOTE : The FD can be disengaged by means of the FD bars
____
 clearing pushbutton switches.

 Two cases may arise:
 a Both FMGCs valid
_
 (FD1 on Capt PFD and FD2 on F/O PFD)
 Action on one pushbutton switch results in:

 -Removal of the bars on the associated PFD
 -Disengagement of the corresponding FD.
 b One FMGC not valid (the opposite FD is presented on Capt
_
 and F/O PFDs)
 Action on one pushbutton switch results in:

 -
Removal of the bars on the PFD associated with the

 pushbutton switch. Action on the second pushbutton switch results in:

 -
Removal of the bars on the associated PFD

 1EFF : ALL 1 22-11-00Page 7 1 1 Feb 01/98 1 1 1CES 1

 FD Disengagement
 Figure 004
 1EFF :  ALL  1  22-11-00 Page 8 
1  1  Feb 01/98
 1  1
 1CES  1