Garmin GTR 200 GTR 200 Installation Manual - Page 49

4.9 Pilot/Copilot PTT Inputs When pulled low, these inputs allow the audio that is present on the PILOT/COPILOT MIC IN to be transmitted over the radio. Active-Low discrete inputs are considered active if either the voltage to ground is ≤3.5 VDC or the resistance to ground is ≤375 . These inputs are considered inactive if the voltage to ground is 6.5-33 VDC or the resistance to ground is >100 k. Pin Name Pin I/O PILOT PTT* 35 In COPILOT PTT* 15 In *Indicates Active Low 4.10 TX Interlock TX Interlock Out is an active low output that indicates that this radio's (GTR 200) COM is transmitting. Connect to another COM's TX Interlock input. TX INTERLOCK OUT will sink 20mA of current and will output a voltage of 1V or less. TX Interlock In is an active low input that desenses (protects) the COM receiver when another COM is transmitting. TX Interlock In is considered active if either the voltage to ground is ≤3.5 VDC or the resistance to ground is ≤375 . TX Interlock In is considered inactive if the voltage to ground is 6.5-33 VDC or the resistance to ground is >100 k. TX INTERLOCK OUT TX INTERLOCK IN* *Indicates Active Low Pin Name Pin I/O 4 Out 5 In 4.11 Discrete Inputs These discrete inputs are active low and are configurable. Active-Low discrete inputs are considered active if either the voltage to ground is ≤3.5 VDC or the resistance to ground is ≤375 W. These inputs are considered inactive if the voltage to ground is 6.5-33 VDC or the resistance to ground is >100 kW. DISC 1* DISC 2* *Indicates Active Low Pin Name Pin I/O 2 In 22 In 190-01553-00 Rev. A GTR 200 Installation Manual Page 4-5