ComStream CM601, Installation And Operation Manual

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32 Command Descriptions 01-0799-401D 08/02
A modulator bit time fault is normally considered a hardware fault and causes the
TxIF output of the modulator to be disabled. If the modulator is configured for
external bit timing (refer to the MB command) and the DTE fails to provide a TT
clock, the modulator will report a bit time fault.
However, this is not a hardware fault condition. In this case, many users keep the
modulator IF transmission enabled, rather than disabling it. If an option card is
installed in the transmit path and OM is set to 1, the modulator bit time fault will
not be supported, but a TT out-of-range fault will be reported by that option card.
PC Pure Carrier (Config) (V)
Use this command to force the modulator to transmit an unmodulated carrier—
also referred to as continuous wave (CW).
PC <setting>
Remote/front panel <setting> parameter values are:
■
0/OFF (default) enables the transmission of a normal, modulated carrier
■
1/ON enables pure carrier transmission
The pure carrier signal is used for diagnostic and system installation. When
enabled, the ST clock on the data I/O connector is reduced to 0 Hz.
From the front panel select:
Config > More > #:Modem > Tx Pure Carrier
PRD Primary Receive Data Rate (Config) (NV)
Use this command to automatically issue all appropriate receive data rate
commands to all cards in the primary receive data path and to automatically
account for any overhead removed by a card from the data stream. The PRD
command represents the data rate that is output from the active I/O card on the
receive side of the CM701/CM601A.
PRD <rate bps>
For the Standard Modem card, the
<rate bps>
parameter range is 9600 to
4375000 bps, with a default of 1544000 bps.
For the Low Speed Modem card, the
<rate bps>
parameter range is 9600 to
512000 bps, with a default of 512000 bps.
From the front panel select:
UserRxData
PRD is a one-way macro command; issuing PRD ? is effective only if no data-
rate-or symbol-rate-related commands have been issued to individual cards since
the PRD value was entered. Issuing PRD ? at such time would return a value of
0
,
indicating that it no longer reflected the system receive data rate.