Operating instructions

INSTALLATION
2-8
Selection logic [or data signals] on pins 1, 3 and 6 enables the Service Monitor to recognize the
connections of an external accessory. The appropriate pins are at TTL levels and are active low as
shown below:
Table 2-2 Accessory socket logic and applications
Accessory Pin 1 Pin 3 Pin 6
Nothing connected High High High
Microphone (press to talk) low high high
External power: Auto zero High Low Low
External power: Peak power High High Low
External power: CW power High Low High
Refer to chapter 3, Operation, for details of using the socket.
A 3.0 meter lead assembly (part No. 43130/591) is available as an optional accessory.
Remote control connections
RS232
The serial port connection requires a 9 way female ‘D’ Type connector. This should be correctly
fitted to the appropriate cable and the locking screws should be used to prevent undue strain from
being applied to the connector housing.
The pin connections are listed below and the pin locations shown in Fig. 2-3 RS232 serial port
connections (as seen facing panel).
Contact Function Contact Function
1 Not connected 6 DSR
2 Rx data in 7 RTS
3 Tx data out 8 CTS
4 DTR 9 Not connected
5 Ground
5
9
1
6
C0783
Fig. 2-3 RS232 serial port connections (as seen facing panel)
The use of a NULL MODEM cable assembly is required for connecting to control equipment such
as PCs.
The connections for 9 way to 9 way and 9 way to 25 way versions are shown in Fig. 2-4.