Comtech EF Data SDM-100A - Manual (Page 107)

SDM-100A Satellite Modem Operation
Rev. 0 3–73
3.2.2.5.3 Utility Interface Functions: Type 1 Operation
Interface Type Displays the interface type (RS-422, V.35, RS-232-C, ASYNC, or
ADPCM) installed in the modem. This is a status window only, and no
changes can be made from this menu.
TX Clock Phase Programs transmit clock phase to Auto, Normal or Invert.
On entry, the current setting for the TX clock phase is displayed.
Press [
↑ ] or [ ↓ ] to select Normal or Invert. Press [ENTER] to execute
the change.
Buffer Clock Programs interface buffer output clock.
EXT. REFERENCE sets this clock source to the master clock (or
terminal timing) external reference, which is received on the DATA
I/O connector on the rear of the modem.
RX SATELLITE sets the output buffer clock to the satellite clock.
TX TERRESTRIAL sets the buffer output clock to recover timing from
the incoming TX data clock.
On entry, the current setting of the interface buffer clock is displayed.
Press [
↑ ] or [ ↓ ] to select EXT. REFERENCE, RX SATELLITE, or TX
TERRESTRIAL for the buffer clock. Press [ENTER] to execute the
change.
Buffer Size This configuration function is used to set the size of the buffer.
On entry, the current buffer length is displayed. Press [
↑ ] or [ ↓ ] to
select the desired buffer size. The buffer size will be displayed in
Milliseconds or Bits. The Interface Utility menu under the Function
Select Utility menu must be entered to change the buffer units to
Milliseconds or Bits. The range which may be selected is 64 to
65,536 bits, in increments of 16, or bypass, which equals 0 bits. If
milliseconds are selected, 0 to 50 ms in increments of 1 ms may be
chosen. Press [ENTER] to execute the change.
Note: To have the modem calculate the buffer depth, set the buffer
units to Milliseconds. When a specific buffer depth is desired, set the
buffer units to bits. To select Bits or Milliseconds, enter the Utility
Interface menu and make the change.
Buffer Center Configuration function used to center the buffer.
On entry, the current status is displayed. Press [
↑ ] or [ ↓ ] to select ON
or OFF. Press [ENTER] to execute the change