Garmin GNC 420A Installation Manual page 38

4.5.1.11 INTEGRITY ANNUNCIATE
The integrity annunciator illuminates when the GPS receiver detects a position error, or is unable to
calculate the integrity of the position.
4.5.1.11.1 ILS/GPS APPROACH Output
Sinks 500 mA when GPS navigation is selected and GPS approach is active or when VLOC navigation is
selected and an ILS channel has been selected. This output may be connected to the ILS Engage input of
an autopilot or flight director to provide higher autopilot gain while the 400 Series unit is operating in the
ILS or GPS Approach modes of operation.
4.5.1.11.2 DEMO MODE SELECT
This discrete input may be used to select Demo Mode on the 400 Series unit. A low on this pin at time of
unit power-up invokes the Demo Mode. Demo Mode allows the 400 Series unit to simulate reception of
GPS satellite signals.
Do not connect DEMO MODE SELECT in an aircraft installation.
4.5.1.11.3 TIME MARK OUT
Time Mark Out is a time reference pulse output once per second, derived from GPS satellite signals.
4.5.2 Annunciators/Switches Electrical Characteristics
4.5.2.1 Annunciators
Pin Name
VLOC ANNUNCIATE
GPS ANNUNCIATE
WAYPOINT ANNUNCIATE
TERMINAL ANNUNCIATE
APPROACH ANNUNCIATE
MESSAGE ANNUNCIATE
OBS ANNUNCIATE
AUTO ANNUNCIATE
INTEGRITY ANNUNCIATE
ILS/GPS APPROACH
All outputs sink up to 500 mA when activated.
4.5.2.2 Switch Inputs
Pin Name
OBS MODE SELECT
CDI SOURCE SELECT
DEMO MODE SELECT
These inputs are considered active if either the voltage to ground is < 1.9 V or the resistance to ground
is < 375 Ω. These inputs are considered inactive if the voltage to ground is 11-33 V
4.5.2.3 TIME MARK OUT
Pin Name
TIME MARK OUT
TIME MARK OUT outputs a 1 ms ± 1 µs wide pulse once every 1.0 s ± 2 ms. TIME MARK OUT is a
logic level output, capable of sourcing 1 mA at up greater than 3.8 V and sinking 1 mA at less than 0.4 V.
4.5.3 Annunciators/Switches Configuration
None.
4.5.4 Annunciators/Switches Calibration and Checkout
Refer to section 5.2.8 for the switches checkout. Refer to section 5.2.9 for the annunciators checkout.
4.5.5 Annunciators/Switches Interconnect
Refer to Figure F-18 on page F-37 for the annunciators/switches interconnect.
Page 4-10
Rev N
CAUTION
Connector
P4001
P4001
P4001
P4001
P4001
P4001
P4001
P4001
P4001
P4001
Connector
P4001
P4001
P4001
Connector
P4001
400 SERIES INSTALLATION MANUAL
Pin I/O
1 Out
2 Out
3 Out
4 Out
5 Out
6 Out
7 Out
8 Out
9 Out
14 Out
Pin I/O
71 In
73 In
75 In
.
DC
Pin I/O
16 Out
P/N 190-00140-02