VEGA Phoenix PSI Data Fax Modem - Manual (Page 79)

Special Functions
692302 5-9
5.4 Caller ID and Selective Call Acceptance
5.4.1 Caller ID Output
Caller ID or CLIP (Calling Line Identification Presentation) is the transmission of the
caller’s telephone number. If this function is enabled at your analog connection, the
PSI-DATA/FAX-MODEM/RS232 can detect, output, and evaluate the caller ID.
The AT%G1 command activates the caller ID output function in the PSI-DATA/
FAX-MODEM/RS232. The caller ID, e.g., for Deutsche Telekom is transmitted after
the first ring, i.e., the modem does not accept the call until after the second ring. The
caller ID is detected by the PSI-DATA/FAX-MODEM/RS232 and output to the
RS-232 interface as follows:
<CRLF>RING<CRLF>
CLIP:0401234…<CRLF>
<CRLF>RING<CRLF>
A telephone number is only then output if a valid caller ID has been detected. It is
only output once for each call. The call is accepted according to S register S0.
5.4.2 Selective Call Acceptance
The PSI-DATA/FAX-MODEM/RS232 can automatically check whether it has been
called from a specific telecommunications cable and establishes a connection. Up
to two telephone numbers can be stored in the device, which the modem compares
and automatically establishes a connection if they match. Store numbers 18 and 19
are reserved for this purpose (&Z18, &Z19).
Example AT&Z18=040 123456789
AT&Z19=0170 123 45 69
If these numbers are stored in these fields and "Selective Answer" is enabled
(AT%G3), the PSI-DATA/FAX-MODEM/RS232 checks each call to see whether
one of the saved numbers has been called. If so, the modem accepts the call and
establishes a connection, regardless of the settings for S register S0. Your control
system therefore does not have to evaluate the caller ID and the modem makes
sure that only the service numbers (&Z18 and &Z19) reach your system, even
without a call back function.
The telephone number evaluation function has a filter function, which also enables
partial evaluation of the telephone number. The evaluation starts with the last digit
and is carried out for each stored digit. If, for example, from the telephone number
0123456789 only the digits 56789 have been stored, all telephone numbers that