Sanden SN3500, Installation Manual

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General Information
82005-IM-K Sandel SN3500 Installation Manual Page 1-6
The SN3500 has a single, conventional set of low level analog inputs for deviation,
flags, etc. from a primary NAV receiver. See the installation diagram for details.
These inputs are not used when the Garmin GNS430/530 ARINC NAV receiver,
which uses ARINC 429 only, is being used. If more than one receiver is used which
has analog signaling, this will require switching relays to feed the single set of
SN3500 inputs. Deviation only NAV converters not providing bearing information are
supported.
There are only low level flag inputs. If it is desired to use a Superflag instead of a low-
level flag from the NAV receiver, a series resistor must be used to the low level ‘+’
input and the ‘-‘ input is grounded. See the installation drawings.
Optional ILS lockout of the GPS selection is provided by an ILS Energize 1/2 input
pins. This feature can be disabled on the NAV maintenance page. In the Master
mode this will cause the SN3500 to revert to and annunciate NAV1 when an ILS is
tuned on NAV1, or NAV2 when an ILS is tuned on NAV2. Disabling of ILS lockout is
called for when the customer does not want ILS lockout operation, or when a GPS
receiver with vertical guidance is used to drive the ILS Energize pin during GPS
operation. In this situation NAV1/GPS1 use ILS Energize 1, and NAV2/GPS 2 use
ILS Energize 2 to display vertical guidance.
For analog receivers, two types of resolvers are supported.
a) An electronic OBS resolver with rotor input and SIN/COS outputs is
provided. An associated DC reference pin must be connected to the stator
low-side connection of the NAV receiver. This may be ground but may
also be a DC reference voltage of approximately 4.5vdc. WARNING: You
must check the NAV receiver wiring before installation planning and before
applying power to the system to prevent NAV receiver damage from
inadvertent miswiring. Refer to the Sandel installation drawing.
This resolver will operate from 30Hz to 500Hz and is calibrated in the NAV
maintenance page.
b) An electronic 400Hz differential resolver is provided for use with 400Hz
receivers such as Collins VIR-30A. This interconnect uses SIN/COS
inputs (Z-ground referenced) and SIN/COS outputs (Z-ground referenced).
1.4.7 Marker Beacon
Three inputs are provided for a Marker Beacon repeater. These are DC level-
sensitive inputs. The thresholds and logic levels are adjusted by selection of the
appropriate equipment type on the MKR maintenance page. Lamp load resistors are
internal.
The SN3500 can also monitor label 222 when marker beacon data is provided from
an ARINC 429 source.
1.4.8 Bearing Pointers (VOR, ADF, and TACAN)