Comtech EF Data SDM-100A - Manual (Page 79)

SDM-100A Satellite Modem Operation
Rev. 0 3–45
3.2.1.6.3 Utility Interface
Interface Type Displays the interface type installed in modem (RS-422, V.35,
RS-232-C, ASYNC, or ADPCM).
This is a status window only, and no changes can be made from this
menu.
Buffer Program Sets the size of the buffer.
On entry, the current buffer length is displayed. Press [
↑ ] or [ ↓ ] to
select the desired buffer size. The buffer size is displayed in seconds
or bits. Enter the Interface Utility menu to change the buffer units to
seconds or bits. If selecting seconds, choose from 1 to 99 ms, in
increments of 1 ms or 0 (Bypass). If selecting bits, choose from 32 to
262,144 bits, in increments of 16 bits. Press [ENTER] to execute the
change.
Note: To have the modem calculate the plesiochronous shift, set
the buffer units to ms. When a specific buffer depth is desired, set
the buffer units to bits.
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.
Terrestrial Interface This selects the interface type for the terrestrial data.
Available only with the ASYNC option.
ASYNC Interface Programs the ASYNC data type for RS-232C or RS-485.
On entry, the current status of the ASYNC data type is displayed.
Press an arrow key to make the selection. Press [ENTER] to execute
the change.
Available only with the ASYNC option.
2- OR 4-Wire This programs the ASYNC interface for either a 2- or 4-wire interface.
Available only with the ASYNC option.
SD Signal Inverts the polarity of the SD signal.
Select either NORMAL or INVERT (inverted) signal poarity. Available
only with the ASYNC or ADPCM options.
RD Signal Inverts the polarity of the RD signal.
Select either NORMAL or INVERT (inverted) signal poarity. Available
only with the ASYNC or ADPCM options.
RR Signal Inverts the polarity of the RR signal.
Select either NORMAL or INVERT (inverted) signal poarity. Available
only with the ASYNCor ADPCM options.