P300H P300 Series Modem Installation and Operating Handbook Page 183
ASYNC ESC CONNECTOR
This connector carries:
An RS232/RS422/RS485 async port for use on ei t her the ESC or Aux channels
An RS232 serial port for log printing & embedded M&C update
An RS422 Station Clock input
The Receive constellation monitor points (i f the Monitor/AGC option is fitted)
ASYNC ESC CONNECTOR
RS232 RS422/ Async port for ESC or Aux channel
RS485
2 2 (a) Async ESC/Aux Input (to satellite)
- 9 (b) Async ESC/Aux Input (to satellite)
3 3 (a) Async ESC/Aux Output (from sate llite)
- 10 (b) Async ESC/Aux Output (from satellite)
1 1 Ground
RS232 Serial port f or Log printing or embedded M&C update
12 Serial Input (RS232 port)
5 Serial Output (RS232 port)
13 Ground
Analog Rx constellation monitor (Rx signal quality)
14 Rx I channel eye
7 Rx Q channel eye
15 Rx symbol clock
13 Ground
RS422 D ifferential Station Clock Input
4 Station Clock (a)
11 Station Clock (b)
13 Ground
RX CONSTELLATION MONITOR PORT.
If the Monitor/AGC option is fi tted it is possible to view a receive constellation (but not the more traditional
`eye pattern`). To display the receive constellation on an oscilloscope, connect the I and Q signals to the
main X/Y inputs, and apply the receive sy mbol clock to the external trigger input of the 'scope. The main
'scope inputs should be set to X/Y di splay, AC coupled, both channels on 200 mV/div, with the trigger from
the external trigger input. S ee `STANDARD LEAD` on the following page.
DIFFERENTIA L STATION CLOCK
This provides a RS422 compatible station clock in addition to the unbalanced 75 station clock BNC
connector. See the menu dialogue in section 6.7.4 on page 89 For a full description of this port.