GTN 625/635/650 TSO Installation Manual Page 6-41190-01004-02 Rev. C6.12 Interface CheckoutThis section describes the checks that must be carried out to verify that systems interfacing to the GTNare communicating properly. Only those interfaces that are connected to the GTN must be verified.6.12.1 Honeywell (Bendix/King) EFS40/50 Interface CheckIf a Honeywell EFS40/50 has been connected to the GTN, the interface should be verified as described inthis section.1. Cycle power to the GTN #1 and acknowledge the prompts until it gets to the Instrument PanelSelf-Test page (see Section 6.11.1).2. Ensure that GPS1 data is displayed by pressing the ―1-2‖ key on the EFS40/50 control panel.3. While the GTN is displaying the self test page, verify that the EFS40/50 is displaying data fromthe GPS source. Note that vertical deviation will not be displayed.Course Deviation: Half-scale left deviation, TO indication, flag pulledActive Waypoint: GARMNVertical Deviation: Half-scale up deviation (only if installation is setup to displayGPS vertical deviation)4. On the GTN verify that an OBS value is displayed (and not dashed out).5. Using a VOR test set verify that the CDI deviation on the EFS40/50 is displayed correctly.6. Cycle power to the second GTN and acknowledge the prompts until it gets to the self test page.7. Switch to GPS2 data by pressing the ―1-2‖ key on the EFS40/50 control panel and repeat steps 3through 5 with the second GTN.6.12.2 Sandel SN 3308 Interface CheckIf a Sandel EHSI has been connected to the GTN, the interface should be verified as described in one ofthe following sections, as appropriate for the installation.6.12.2.1 One GTN/One SN 33081. Cycle power to the GTN and acknowledge the prompts until it gets to the Instrument Panel Self-Test page (see Section 6.11.1).2. Ensure that the SN3308 is receiving valid heading.NOTEThe Vertical Deviation Indication will not be displayed unless the SN3308 is receivingvalid heading.3. While the GTN is displaying the self test page, verify that the SN3308 is displaying the followingdata from the GPS source.Course Deviation: Half-scale left deviation, TO indication, flag pulledVertical Deviation: Half-scale up deviation, flag pulledActive Waypoint: GARMN4. On the GTN verify that an OBS value is displayed (and not dashed out).5. Acknowledge the self test on the GTN by touching the ‗Continue‘ key.6. Select VLOC on the GTN and verify that the SN3308 displays NAV 1 or NAV 2 (depending onwhat navigation source the GTN is).7. Using a VOR test set verify that the CDI deviation on the SN3308 is displayed correctly.
