Calling Line Identifier
CMX602A
Figure 8b : Bellcore On-hook System Signals
Other On-hook Systems
ETS 300 659-1 also allows for systems where the FSK transmission is preceded by a Dual Tone Alerting signal
similar to that used by BT but without a line reversal (section 6.1.2a) or by a Ringing Pulse Alerting Signal
(section 6.1.2b).
The U.K. CCA (Cable Communications Association) specification TW/P&E/312 precedes the FSK signals by a
200 to 450ms ring burst. AC and DC line terminations during FSK reception are optional.
Mercury Communications Ltd. specification MNR 19 allows for either the BT system or that specified by CCA.
As these are all slight variants on the BT and Bellcore systems, they can also be handled by the CMX602A.
ã 1998 Consumer Microcircuits Limited
15
D/602A/4
CMLMICRO [ CML MICROCIRCUITS ]
