Comtech EF Data CDM-740 - Manual (Page 71)

CDM-740 Advanced Satellite Modem Revision 0
Front Panel Operation MN-CDM740
5–19
5.5 SELECT: Test
TEST: Mode BERT Pattern
(
◄► )
Select Mode, BERT, or Pattern using the ◄ ► arrow keys, then press ENTER.
5.5.1 TEST: Mode
Modem Test Mode: Normal Tx-CW Tx-1/0
(
◄► E)
Select Normal operation, Tx-CW, or Tx-1/0 using the ▲ ▼ arrow keys, then press ENTER.
Note the following:
Selection Description
Normal
(Normal) This clears any test modes and places the unit back into an
operational state.The TEST MODE LED on the CDM-740 front panel will turn
OFF.
Tx-CW
(Transmit CW) This is a test mode that forces the modulator to transmit a pure
carrier (unmodulated). The TEST MODE LED on the CDM-740 front panel will
turn ON.
Tx-1/0
(Transmit an alternating 1,0,1,0 pattern) This test mode forces the modulator
to transmit a carrier modulated with an alternating 1,0,1,0 pattern at the currently
selected symbol rate. This causes two discrete spectral lines to appear, spaced
at +/- half the symbol rate about the carrier frequency. This mode is used to
check the carrier suppression of the Modulator. The TEST MODE LED on the
CDM-740 front panel will turn ON.
5.5.2 TEST: BERT
Tx BERT State: Off On
(
◄► E)
Set the Tx BERT State as On or Off using the ◄ ► arrow keys, then press ENTER. When On is
selected, the Test Mode LED on the CDM-740 front panel will turn ON.
5.5.2.1 TEST: Pattern
Tx BERT Pattern: 2E23-1 2047
(
◄► E)
Select 2E23-1 or 2047 using the ◄ ► arrow keys, then press ENTER. Note the following:
Selection Description
2E23-1 A pseudo-random data pattern of 2E23 –1, compatible with standard BERTs.
2047 A pseudo-random data pattern of 2E11 –1, compatible with standard BERTs.