Comtech EF Data SDM-309B - Manual (Page 117)

M&C and Interfaces SDM-309B Satellite Modem
4-4–40 MN/U-SDM309B Rev. #
4.2.2.11.4 Insert Data Output
The insert 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, SW2 position 5 & 6 must be closed (close to PCB) and SW2 position 7
& 8 must be open (away from PCB). To use the DB15 connector output, SW2 position 5
& 6 must be open and SW2 position 7 & 8 must be closed.
4.2.2.11.5 External Reference Clock
The external reference clock 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, SW3 position 1 & 3 must be closed (close to PCB) and SW3
position 2 & 4 must be open (away from PCB). To use the DB15 connector input, SW3
position 1 & 3 must be open and SW3 position 2 & 4 must be closed.
4.2.2.11.6 Drop Output/Insert Input (SW4)
When the Drop Data Output is to be connected directly to the Insert Data Input on a
single breakout panel the loop function may be used. Switch 4 in the UP position
eliminates the need for an external cable from the Drop Data Output to the Insert Data
Input. When the Drop Data Output is not to be connected to the Insert Data Input on the
same breakout panel, the Normal function must be used. Switch 4 in the DOWN position
allows normal operation.
4.2.2.11.7 Drop Data Output DCE/DTE Select (SW5)
When the Drop Data Output is to be connected to another Drop Data Input the DTE
position (DOWN) must be selected for SW5. This puts the Drop Data Output on pins 1
and 9 on J2. When the Drop Data Output is to be connected to an Insert Data Input, the
DCE position (UP) must be selected for SW5. This puts the Drop Data Output on pins 3
and 11 of J2.