Sandel
Avionics
SN3308 Navigation Display
Installation Manual
90106-IM-G(4) Installation Manual W SIG.doc
Page 15
remote host PC. See the installation drawings for the recommended method for
connecting channel 2.
Both of these ports support RS422 transmission which can be connected if desired.
The RS-232 and RS-422 transmitters are on separate pins and operate
simultaneously.
Note that the same receiver pins are used for either RS232/422. The SN3308 uses a
differential receiver compatible with both standards. RS-232 is connected to the
minus input of the receiver, and the plus input is grounded because RS-232 is an
inverted signal, i.e. –10v is logic one and +10v is logic zero.
1.4.10 GARMIN GNS430 GPS/VOR/LOC Combination Receiver
The complete interface between the SN3308 and the GNS430 can be done using the
ARINC 429 ports. The ARINC 429 data carries all GPS and VOR/LOC data, resolver
information and flags & annunciators.
For a single GNS430 installation, the SN3308 429 Port 1 is used to receive GPS
data, and either Port 2 or Port 3 is used to receive VOR/LOC data. If a DME is to be
interfaced to the SN3308 as well, it must be on Port 2 which will necessitate
connecting the GNS430 VOR/LOC to Port 3. ARINC 429 output data
from
the
SN3308 must go to the GNS430 GPS 429 Input port (see installation drawing). No
composite NAV signals are required, because the bearing pointers receive data via
the ARINC 429.
For a dual GNS430 installation, a relay is required to switch the ARINC 429 data from
the two VOR/LOC receivers into the single available SN3308 input port. In addition,
the composite NAV signal from the two VOR/LOC receivers are connected to the
SN3308 to provide uninterrupted NAV bearing pointers irrespective of the selected
receiver. As in a single GNS430 installation, ARINC 429 output data
from
the
SN3308 must go to the GNS430 GPS 429 Input ports.
In some dual GNS430 installations, the second GNS430 is wired to a mechanical
indicator and will not be selectable for primary navigation on the SN3308. In this
case, composite NAV and GPS ARINC 429 data from the second receiver can be
connected to the SN3308 to provide RMI bearing pointers only. The SN3308 is
configured as though it were connected to a single GNS430, with the additional
bearing pointer sources enabled. NOTE: It is not possible to enable GPS 2 as a
bearing pointer source without having it also available as a primary nav source.
After installation, ensure that the following setup items are configured on both the
SN3308 and the GNS430:
