- catch the (serial) output with some COMM components you grab from torry.net, be prepared to handle quick streams of info, and wait a long time for the next stream ;-)
useually something about the baudrate is specified in the manual of the pabx, guess you can connect a (serial) printer to it. If you can only connect parallel printers, the expect to build some parallel I/O board, or program a parallel printerort for input (but almost none can handle 8 bits in parallel)
If there is a Ethernet interface, youre very lucky, there must be some protocol to read the info from there
- parse this datastream, and see what you can get from it
HTH
TonHu