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Comtech EF Data SDM-309B User Manual

Page 62

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SDM-309B Satellite Modem

Operation

MN/U-SDM309B Rev. #

3–31

BBLoopBk

*Programs the modem for baseband loopback
operation.

When baseband loopback is turned on insert
data is looped back on the customer side of
the interface.

Note: The drop data is hard wired into
loopback causing the BBLoopBk function to
affect only the insert data. See Figure 3-10 for
a block diagram of Baseband loopback
operation.

On entry the current status is displayed with
the flashing cursor on the first character. Use
the arrow keys to select ON or OFF. Press the
“ENTER” key to execute the change.

INTF_LBk

*Programs the modem for interface loopback
operation.

When interface loopback is turned on data is
looped back on the modem side of the
interface. See Figure 3-11 for a block diagram
of Interface loopback operation.

On entry the current status is displayed with
the flashing cursor on the first character. Use
the arrow keys to select ON or OFF. Press the
“ENTER” key to execute the change.

Note: Interface loopback only works when
the TX data rate matches the RX data rate.

TX CODE

Programs the transmitter for “AMI”, “HDB3”, or
“B8ZS” data.

On entry the current coding format is
displayed. Use the arrow keys to select the
desired coding format. Press the “ENTER”
key to execute the change.

RX CODE

Programs the receiver for “AMI”, “HDB3”, or
“B8ZS” data.

On entry the current coding format is
displayed. Use the arrow keys to select the
desired coding format. Press the “ENTER”
key to execute the change.

TX_2047

*Programs the modem to insert a 2047
pattern in place of the normal transmit data.

On entry the current status is displayed with
the flashing cursor on the first character. Use
the arrow keys to select ON or OFF. Press the
“ENTER” key to execute the change.