Operating instructions

OPERATING MANUAL 2945A
46882-311D 2-7
C1785
EARTH SHIELD
13
45
2
6
7
Fig. 2-2 Accessory in/out socket pin numbers
The socket is used for connecting dedicated accessories such as directional power heads and
microphones with press to talk switching capabilities.
Selection logic [or data signals] on pins 1,3 and 6 enables the Service Monitor to recognise the
connections of an external accessory. The appropriate pins are at TTL levels and are active low
(L) 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 metre lead assembly (part No. 43130/591B) 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 appropriate cable and the locking screws should be used to prevent undue strain from
being applied to the connector housing.