aka
TAP. The
protocol used to communicate with
alphanumeric paging services. It's usual means of operation is a
300bps dialup modem.
A typical session goes something like:
Server Client
ID= ESC PG1 CR
114 Welcome CR ACK CR
ESC [ p CR STX Pager ID CR
Pager Message CR ETX Checksum CR
211 Message sent CR ACK CR
ESC EOT CR
115 Goodbye CR ESC EOT CR
Checksum algorithm:
Sum all characters making up message (everything between and including
STX/
ETX) then transmit the checksum as 3 bytes:
Checksumdigit = (((Checksum>>8)%16)+'0');
transmit(Checksumdigit);
Checksumdigit = (((Checksum>>4)%16)+'0');
transmit(Checksumdigit);
Checksumdigit = (((lChecksum)%16)+'0');
transmit(Checksumdigit);