NGT—Overview and specifications
52 NGT Transceiver System Technical Service Manual
Pinouts of the 15-way GPIO connector on the junction box
Figure 18: Front view of the 15-way GPIO connector on the junction box
Table 16: Pinouts of the 15-way GPIO connector on the junction box
Pin no. Function Input/output Signal level
1 RTS Output RS232
2 RS232 Receive data Input RS232
3 RS232 Transmit data Output RS232
4 Ground 0 V
5 Tx audio (50 kΩ balanced) Input 300 mV p–p ALC threshold
6 External alarm relay Contacts rated 50 V, 1 A
7 External alarm relay Closed for alarm
8 A rail Output +13.6 V nominal
9 CTS Input RS232
10 PTT Input 5 V TTL logic active low
11 Morse Input 5 V TTL logic active low
12 Spare Input/output 5 V TTL logic
13 Spare Input/output 5 V TTL logic
14 System audio Output 1 V p–p (maximum load
1kΩ)
15 Tx audio (50 kΩ balanced) Input 300 mV p–p ALC threshold
NOTE
Pins 6, 7 and 9 may be linked internally to select normally open or closed.
The pins can be configured to switch to ground or the A rail.
1
915
8