Post Installation Configuration & Checkout190-01499-02 GTX 3X5 Transponder TSO Installation ManualRev. 9 Page 6-12Discrete InFor pinout information, refer to section 5.NOTEThe source priority is based upon the selections made during configuration. Refer to section 3.10.Table 6-7 Discrete InputsFigure 6-11 Discrete In PageFunction Selection DescriptionAUD MUTE All discrete inputs The audio output will be muted until the discrete is opened.This is connected to a higher priority audio such as TAWS.AUD CNCL OffP3251-37When this discrete is grounded by a momentary switch, audioalerts are canceled.IDENT OffP3251-36When this discrete is grounded by a momentary switch, the SPIactivates.STANDBY OffP3251-14When this discrete is grounded, the unit will go into standbymode. Ensure standby select is not configured if a transpondercontrol format (remote or transponder formats) is used tocontrol the transponder.SQUAT OffP3251-57This input determines the on-ground status of the aircraft. It isactive low, and a ground on this input can be configured tomean On Ground or In Air.AIR DATA OffP3251-58Switches between two ARINC 429 ADC sources or two EFISADC sources. Source 1 and 2 are set during configuration.Source 1 is used when the discrete is open and Source 2 is usedwhen the discrete is grounded.ALT DATA All discrete inputs Selects between two pressure altitude sources.ID SLCTAll discrete inputson main board(P3251)Selects the system ID and overrides configuration setting. GTX 1system ID is selected when this discrete is open. GTX 2 systemID is selected when the discrete is grounded.GILLHAM On, OffActivates all ten Gillham/Gray code inputs. If set to OFF, theinput pins are available for configuration to other discrete inputfunctions.TIS-A(GTX 335 Only) All discrete inputs When this discrete is momentarily grounded, TIS-A will togglebetween operate/standby.
