Comtech EF Data CDM-570 - Manual (Page 125)

CDM-570/570L Satellite Modem with Optional IP Module Revision 12
Front Panel Operation MN/CDM570L.IOM
5–39
5.2.2.2.6 MONITOR: ODU (CDM-570L ONLY)
See Appendix L. CDM-570L ODU (BUC, LNB) OPERATION for complete details
about this modem-specific menu branch.
Outdoor Unit Monitor:
BUC LNB (▲ ▼,ENTER)
For the CDM-570L only: This menu branch is used to monitor a BUC (Block Up Converter) or
LNB (Low-Noise Block Down Converter), if connected. Use the
▲ ▼ arrow keys to select BUC
or LNB. Press ENTER to continue or CLEAR to return to the previous menu.
5.2.2.3 SELECT: TEST
TEST: Norm IF> Dig> I/O>
RF> Tx-CW Tx-1,0(◄ ►,ENT)
This menu branch is used to execute a variety of test modes. Use the ◄ ► arrow keys to select
Norm, IF >, Dig> I/O>, RF>, Tx-CW, or Tx-1,0, and then press ENTER.
Note the following:
Selection Description
Norm
(Normal) This clears any test modes or loopbacks, and places the modem back into an operational
state.
IF>
(IF Loopback) This test mode invokes an internal IF loop. This is a particularly useful feature, as it is
used to perform a quick diagnostic test without having to disturb external cabling. Furthermore, all of
the receive configuration parameters are temporarily changed to match those of the transmit side.
During an IF Loop, the Tx carrier continues to be transmitted. See Figure 5-4.
When Norm is again selected, all previous values are restored.
Dig>
(Digital Loopback) This test mode invokes a digital loopback, which loops data at the output of the
framer/scrambler on the transmit side and back into the deframer/descrambler on the receive side. If
concatenated Reed-Solomon FEC is being used, this is also included in the digital loop. See Figure
5-4.
I/O>
(Inward/Outward loopback) This test mode invokes two distinct loopbacks:
• The Inward Loop takes data being received from the satellite direction and passes it directly to
the modulator.
• Simultaneously, the Outward Loop is invoked, whereby data being fed to the transmit data
interface is routed directly back out of the receive data interface. See Figure 5-4.
RF>
(RF Loopback) Useful for performing a satellite loopback, this test mode is almost identical to the IF
loop mode: All receive configuration parameters are temporarily changed to match those of the
transmit side; however, no internal connection is made.
When Norm is again selected, all previous values are restored.
TX-CW
(Transmit CW) Used for measuring phase noise, this test mode forces the modulator to transmit a
pure carrier (unmodulated).