Mounting And 4.2 Equipment Setup And - Garmin GDL 90 Installation Manual

4 Post Installation Configuration & Checkout Procedures
Once the GDL 90 unit has been installed, configure the unit for the particular installation and then
complete these checkout procedures to verify proper operation for continued airworthiness. The steps
that are not applicable to a particular installation may be skipped. A checkout log sheet, included on page
4-20, is to be filled out during the checkout procedure. The completed checkout log sheet should be
maintained with the aircraft permanent records.
Operating the GDL 90 without RF terminations on the Top or Bottom UAT Antenna
ports can result in equipment damage. Always operate the GDL 90 with the Top and
Bottom UAT Antenna ports terminated with a VSWR ratio of 3.0:1 or less.
4.1 Mounting and Wiring Check
Verify that all cables are properly secured and shields are connected as the install drawings indicate.
Installation may require that you check the movement of the aircraft controls to verify that there is no
interference.
4.2 Equipment Setup and Configuration
Prior to system operation, the GDL 90 must be configured for the particular installation. The system
setup and checkout functions are accessed by connecting a PC or terminal to the GDL 90 serial
Maintenance port. Use the commands as described in the following sections, with these port settings:
38,400 baud
8-bit data
1 stop bit
no parity
no flow control
4.2.1 How to Use the GDL 90 Maintenance Port with HyperTerminal
1. Position the aircraft so that it can see the GPS satellites, well away from any major structures.
2. Connect a computer to the Maintenance Port.
3. Startup the computer and run the HyperTerminal program, as follows:
a. Click on Start, go to Programs > Accessories > Communications > HyperTerminal, and
click on "HyperTerminal".
b. In the "Connection Description" dialog box, enter "GDL90". You can start up
HyperTerminal with this connection name the next time you need to use the Maintenance
Port. Click on OK.
c. In the "Connect Using" dialog box, use the drop-down list to select your communication
port. Typically, it will be COM1.
d. In the "Properties" box, for "Bits per Second" select 38400 from the drop-down list.
Leave the "Data bits" set to 8, "Parity" set to None, and "Stop bits" set to 1. Set "Flow
Control" to None, and then click OK.
4. HyperTerminal is now set up to communicate with the GDL 90. Power up the GDL 90, and you
should see some lowercase Xs displayed, then several lines of text. After that, when you press
the <enter> key, you should see the ">" prompt character display. If this doesn't work, use the
Properties menu button to double-check the HyperTerminal settings, and check the wiring to the
GDL 90 to be sure the Maintenance port is connected properly.
GDL 90 Installation Manual
Post-Installation Configuration and Checkout
CAUTION
560-1049-02 Rev. B
4-1