Case Communications Mayze 24, Reference Manual, Page: 82 / 166

If the busy (engaged) tone is detected, the modem clears the call and
responds with the message:
BUSY
If the forty-second count-down time expires without a successful
handshake, the modem clears the call and responds with the message:
NO ANSWER
If the modem detects a dial tone after dialling is completed, then the call
clears and the modem responds with the message:
DIALTONE
6.2.6 The Blacklist
National regulations specify a maximum number of times that a number
may be automatically redialled within a specified time interval, if it is
busy, engaged or unobtainable when first dialled.
The telephone number blacklist is used to prevent the modem from
exceeding this limit when in autodial mode (that is, when the
U modifier
has been included in the dial string).
The following conditions apply to this feature:
– The blacklist operates on PSTN calls only.
– Twenty blacklisted numbers can be accommodated at a time.
– Each number dialled with the
U
modifier is entered onto the blacklist,
and cleared only if the call is successful. A successful call is defined as
one which results in the response
CONNECT XXXX .
– If the modem has blacklisted the maximum of 20 numbers, it will not
allow another number with the
U
modifier to be dialled until one of the
previously blacklisted numbers has timed out.
UK regulations are given in Appendix C. Note that when the modem is
being controlled by external communications software, the user must
ensure that this is set up so that repeat dialling obeys the regulations.
X460-306851 Issue 1 6-6 Rev.0