Comtech EF Data SDM-300A, Installation And Operation Manual

Page: 111 / 398

Operation SDM-300A Satellite Modem
3–58 Rev. 4
3.3.13.3 Utility Interface
Refer to Figure 3-19.
TX OVERHEAD TYPE Select None, IDR, IBS, DROP & INSERT, or ASYNC for TX overhead
type.
Note: Overhead types are selectable only when Custom is selected for
modem type in the Utility Modem Type menu.
RX OVERHEAD TYPE Select None, IDR, IBS, DROP & INSERT, or ASYNC for RX
overhead type.
Note: Overhead types are selectable only when Custom is selected for
modem type in the Utility Modem Type menu.
TX TERR INTERFACE Displays the TX interface type EIA-232, EIA-422, V.35, or G.703.
Note: G.703 is available only when the overhead interface PCB is
installed.
RX TERR INTERFACE Displays the TX interface type EIA-232, EIA-422, V.35, or G.703.
Note: G.703 is available only when the overhead interface PCB is
installed.
BUFFER PROGRAM Buffer unit program function. Select MILLI-SECONDS or BITS.
Note: To have the modem calculate the plesiochronous shift, set the
buffer units to MILLI-SECONDS. For a specific buffer depth, set the
buffer units to BITS.
FRAMING STRUCTURE Displays the currently selected framing type and structure of the data.
This function is used with the buffer program in ms for plesiochronous
buffer slips.
Upon entry, the framing type (T1 or E1) is displayed on Line 1. The
framing structure of each type (None or G.704) is displayed on Line 2.
Press [
←
] or [
→
] and [
↑
] or [
↓
] to select framing structure and type.
Press [ENTER] to execute the change.
RTS TX-IF CNTRL Programs the modem to allow a Request To Send (RTS) signal to
enable the output when data is ready for transmission.
Press[
←
], [
→
], [
↑
], or [
↓
] to move the flashing cursor. Press [ENTER]
to execute the change.
TX DATA PHASE TX data phase relationship. Use this option to select Normal or Invert
for the TX data relationship to the selected TX clock.
Upon entry, press [
↑
] or [
↓
] to make the selection. Press [ENTER] to
execute the change.
RX DATA PHASE RX data phase relationship. Use this option to select Normal or Invert
for the RX data relationship to the selected RX clock.
Upon entry, press [
↑
] or [
↓
] to make the selection. Press [ENTER] to
execute the change.
E1 INSERT CRC E1 INSERT CRC enable function. Use this option to turn the CRC-4 on
the insert side of the E1 ON or OFF. The default for this function is ON.
If the equipment cannot use the CRC-4 signal, disable the signal by
selecting OFF.
Note: This selection is available only when D&I is enabled.