how to test a bill-poster of a telephone?

[fa_07]

how to test a bill-poster of a telephone?

[torbjorn]

That depends on which kind of billing pulses is used in the telephone network where the unit is to be used.
Some networks use 12 kHz or 16 kHz billing pulses while other ones reverse the polarity of the line current to indicate a billing pulse.

Information on telephony standards, at least for european countries, can be found at http://pda.etsi.org/pda/queryform.asp . A good general standard (but a huge PDF document) that contains aspects on most european networks is the ETSI EN 300 001 .