Comtech EF Data SDM-309B - Manual (Page 116)

SDM-309B Satellite Modem M&C and Interfaces
MN/U-SDM309B Rev. # 4-4–39
DROP DATA OUTPUT DDO-A
DDO-B 37
38
TERRESTRIAL TX DATA TER_TXDAT 5
TERRESTRIAL RX DATA TER_RXDAT 7
INSERT DATA INPUT IDI-A
IDI-B 39
40
PRIMARY COMMON PRI_COM 10
PRIMARY NORMALLY OPEN PRI_NO 43
PRIMARY NORMALLY CLOSED PRI_NC 27
SECONDARY COMMON SEC_COM 11
SECONDARY NORMALLY OPEN SEC_NO 44
SECONDARY NORMALLY CLOSED SEC_NC 28
DATA SET READY DSR 48
4.2.2.11 Rear Panel Switches
Switch 1 through switch 3 are used to select signals through the BNC connectors or the
DB15 connectors. Switch 4 is used to select normal or loopback conditions. Switch 5 is
used to select DCE or DTE Drop Data Output pin selection. Figure 4-13 shows the
layout of the rear panel switches. Table 4-3 describes their function. Figure 4-14 and
Figure 4-15 is the schematic diagram for the breakout panel.
4.2.2.11.1 Drop Data Input
The drop data input signal has two input sources. The BNC connector has the
unbalanced input signal and the DB15 connector has the balanced input signal. To use
the BNC connector input, SW1 position 1 & 2 must be closed (close to PCB) and SW1
position 3 & 4 must be open (away from PCB). To use the DB15 connector input, SW1
position 1 & 2 must be open and SW1 position 3 & 4 must be closed. The switch pack is
located on the rear of the breakout panel.
4.2.2.11.2 Drop Data Output
The drop data output signal has two outputs. The BNC connector has the unbalanced
output signal and the DB15 connector has the balanced output signal. To use the BNC
connector output, SW1 position 5 & 6 must be closed (close to PCB) and SW1 position 7
& 8 must be open (away from PCB). To use the DB15 connector output, SW1 position 5
& 6 must be open and SW1 position 7 & 8 must be closed.
4.2.2.11.3 Insert Data Input
The insert data input signal has two input sources. The BNC connector has the
unbalanced input signal and the DB15 connector has the balanced input signal. To use
the BNC connector input, SW2 position 1 & 2 must be closed (close to PCB) and SW2
position 3 & 4 must be open (away from PCB). To use the DB15 connector input, SW2
position 1 & 2 must be open and SW2 position 3 & 4 must be closed.