PRINCIPLES OF OPERATION
If the M lead is in the Idle condition then the M lead information is
retransmitted every 60 seconds. This causes a short break in the voice
path every 60 seconds.
Therefore it is important that on systems which do not use E&M signal-
ing (e.g., open lines for traders) that the M lead is somehow forced into
the Busy state. It is not recommended that this is done using the diagnos-
tic software since this would force on the Channel Alarm light on a per-
manent basis and this could mask real channel alarms.
The -002 version of the card supports FAX bypass at the 6.4 kHz channel
data rate. The FAX data rate is normally 4.8 kHz, with a 2.4 kHz
fallback rate if external line conditions dictate. FAX data is sent over the
voice channel. No voice traffic is possible during a FAX session.
The -004 version of the card supports FAX bypass at the 9.6 kHz or 6.4 kHz
channel data rate. The FAX data rate is normally 9.6 kHz with fallback
rates of 7.2, 4.8 and 2.4 kHz as defined by ITU-T.4.
NOTE
The 9.6 kHz channel data rate is available only in TMS-
3000.
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