m4a5a_v320_eng (14.02.2013)
- 34 -
Kompetent für Elektroniksysteme
m4a5a_v320_eng (14.02.2013)
- 35 -
Kompetent für Elektroniksysteme
Hardware Configuration
The Major 4a/5a can be configured for 2-wire and 4-wire connection. Starting with software version
2.0 switching from 2-wire to 4-wire is done by programming register 051/4.
Two/Four-Wire Configuration
Two-Wire Connection using FT630
Over longer distances the radio set can be controlled via a 2-wire line. If PTT is keyed at the Major, a
DC voltage is applied to the line in addition to the audio signal. This voltage is analyzed in the FT630-
2 and the PTT relay turns on the transmitter. In the reverse situation the FT630-2 is able to apply a
DC voltage to the line if an incoming signal (squelch) is present.
If the DC voltage is used for transmitter keying as well as for detection of an incoming signal, no
transmission is possible while a squelch signal is detected.
Instead of the FT630-2 (DC) the line interfaces FT634aC or FT634 can also be used. For these no
DC coupling is necessary and additional features are available, e.g. the transmission via digital in-
/outputs (alarm in case of dysfunction, housebreaking, fire...) and remote channel control.
Register 069/1 defines if PTT keying is conducted by the PTT keying tone or by a DC voltage.
Summary of Contents for Major 4a
Page 1: ...Major 4a Major 5a ...