Figure 2-3. External Connections - Microwave Data Systems MDS 4310 Installation, Operation & Field Maintenance

Do not use a full RS-232 cable for connection to the
connector. Cross-coupling between wires in the cable can cause
improper operation. Use only the pins required for the
application. (Refer also to Note 2 in Table 2-1.)
DATA AND
MODULATION
INTERFACE
DC POWER
Radios without internal modems...
The connector allows a unbalanced 600Ω voice frequency interface to the radio
INTERFACE
with additional pins for transmitter keying (PTT), alarm, and diagnostic indications.
When an optional MDS internal modem is installed...
The connector allows a standard RS-232 interface. The full handshake
INTERFACE
implemented includes TXD, RXD, RTS, CTS, and DCD. DSR is true whenever the radio and
modem are powered up, and the transmitter is automatically keyed when RTS goes high.
CTS is raised after the programmable delay (factory default is 10 ms), to allow time for the
synthesizer to change frequency and for the receiver at the other end of the link to unsquelch.
This time can be modified by the user to suit specific system timing requirements with the
HHT.
When equipped with an optional internal modem, the MDS 4310 "SMART" Data
Transceiver interfaces directly to any data terminal or RTU that supports the Bell 202,
RS-232 format. This considerably simplifies installation, since the levels between the radio
and modem can be preset at the factory, eliminating field measurements or adjustments. PTT
control and delay are handled automatically by the radio with the RTS/CTS handshake. Even
with the internal modem, the MDS 4310 "SMART" Data Transceiver allows programming
and diagnostic information to be accessed without disassembly of the transceiver enclosure.
MDS 05-2415A01, Rev. A
NOTE
INPUT
13.8 VDC
ANTENNA CONNECTOR &
TRANSMISSION LINE

Figure 2-3. External Connections

INTERFACE
INSTALLATION 2-5