—
194
data. These two pins go ON when the printer is ready to accept data. In the 1 byte mode they go OFF after each character is received. In the 1 block mode they only go OFF when the printer’s buffer approaches capacity. In both cases they will stay OFF if the buffer is too full to accept more data.
H XON/XOFFprotocol
The XON/XOFFprotocolusestheASCII characters(DC1)
and (DC3) (sometimes called XON and XOFF, respectively) to communicate with the computer. When the printer’s buffer ap- proaches capacity this printer will send a DC3 (ASCII 19) on TXD (pin 2) to tell the computer that it must stop sending data. When the printer is able to receive more data it sends a DC1 (ASCII 17) on TXD. The computer can then send more data until the printer sends another DC3.
■ACK protocol
In the ACK protocol, this printer sends an ACK (ASCII 6) on TXD (pin 2) each time that it is prepared to receive a byte of data.
Wnlpnmltlwkbml
Ctmcl,t!wu.1
