Garmin GNS 480 Installation Manaul page 108

Post-Installation Configuration & Checkout
Figure 3-29. Interface Monitor Function Display - Page 3
This page displays the current values of the synchro heading, baro potentiometer and 26VAC reference
inputs.
Press the MAIN line select key to return to the Interface Monitor Function Display - Page 1.
Details for each of the inputs that can be monitored are shown in Table 3-6.
For each GNS 480 ARINC 429 input that is used, verify that data is being received. If no data is being
received, ensure that (i) the source equipment is turned on, (ii) the ARINC 429 input type and speed has
been set up correctly, and (iii) the wiring is correct.
For each discrete input that is connected to the GNS 480, exercise the discrete and verify that the
appropriate discrete changes from a '0' to a '1' when activated (the CDI Select input will momentarily
change to a 'T' when exercised).
For each GNS 480 serial input that is used, verify that data is being received. If no data is being received,
ensure that (i) the source equipment is turned on, (ii) the serial port input RX type has been set up
correctly, and (iii) the wiring is correct.
If synchro heading is supplied to the GNS 480, verify that the synchro heading is displayed and agrees
with the value provided by the heading source. If the synchro heading is dashed out, ensure that (i) the
source equipment is turned on, (ii) the heading valid discrete is VALID (P5-57 = '1'), (iii) the 26VAC 400
Hz reference is being supplied, and (iv) the wiring is correct.
If a baro pot is connected to the GNS 480, verify that the baro-correction is displayed and agrees with the
altimeter baro-correction. If the baro-correction value does not vary with the altimeter value, ensure that
(i) the baro-correction has been properly calibrated, and (ii) the wiring is correct.
3-28 560-0982-01 Rev L GNS 480 (CNX80) Installation Manual