Garmin GMA 240 Installation Manual - Page 27

4.4 Configuration Pins 4.4.1 External Configuration Pins The following pins may be used to change the configuration of the installation as described. Pin Connector Pin Name Description 16 P2401 MASQ Ground to disable Master Avionics Squelch circuitry. This INHIBIT* will cause alerts and selected radios to be heard at all times IN without needing to exceed the mute threshold. This causes an increase in background noise from the inputs during quiet output. 29 P2401 CREW Ground to configure the unit for CREW ICS isolation. In this ISO* IN configuration, the copilot headset jack should be wired in parallel with the pilot headset output. The mics are wired as normal. In this mode, when the PILOT ISO button is selected, the pilot and copilot will hear each other, but will be intercom isolated from the passengers. 13 P2402 PILOT ISO Ground to allow Music audio to be heard by the pilot during MUSIC* IN pilot isolate mode. 19 P2402 BUTTON Ground to enable beep tone annunciation of button presses PRESS TONE ENABLE* IN 30 P2402 MUTE ON Ground to enable muting of other selected radios during mic COM TX* selected COM transmission (mic-selected COM is still heard, IN but not other selected radios) * Denotes Active Low (Ground to activate) GMA 240 Installation Manual 190-00917-01 Page 4-5 Rev. B