*) with internal pull-up
1 transmission rate: 600, 1200, 2400, 4800, 9600, or 19200 baud
2 parity: even, odd, none, or ignore
3 word length: 7, or 8 bits
4 number of stop bits: in receive mode the printer accepts 1, or 2 stop bits. the printer transmits always two stop bits.
transmission protocols:
1 dtr - ready/busy
2 xon/xoff
3 xon/xoff + dtr