14 MDS SD4 Startup Guide 05-4669A01, Rev. B
COM2 CONNECTIONS
The COM2 connector (Figure 10) is used to connect the radio to an
external DTE telemetry device that supports the EIA/RS-232 or
EIA/RS-485 (balanced) format, depending on how the radio is configured. The radio supports data rates of 300, 1200, 2400, 4800, 9600,
19200, 38400, 57600, and 115200 bps (asynchronous data only).
The
COM2 connector mates with a standard DB-9 plug that is avail-
able from many electronics parts distributors. Table 5 provides
detailed pin descriptions for the
COM2 data connector in RS/EIA-232
mode.
NOTE:To prevent unintended keying of the transmitter on RTS, set
RTSKEY to OFF, or do not connect to Pin 7 (RTS) of the COM2 port.
Pin Descriptions—RS/EIA-232 Mode
Table 5 lists the COM connector pin functions when configured to
operate in RS/EIA-232 mode. For RS/EIA-422/485 mode, refer to the
Reference Manual.
NOTE: The radio is hard-wired as a DCE device.
Figure 10. COM2 Connector (DB-9F)
As viewed from outside the radio
Table 5. COM2 Pin Descriptions—RS/EIA-232
Pin
Number
Input/
Output Pin Description
1 OUT DCD (Data Carrier Detect/Link)—A low indicates
signal received.
Digital Modem Selections: Digital carrier detect
Analog Modem Selections: Squelch indicator
2 OUT RXD (Received Data)—Supplies received data to
the connected device.
3INTXD (Transmitted Data)—Accepts TX data from the
connected device.
5
96
1