Lexmark Printer manual Data Flow Control Protocol

8-39

Interfaces

Parity

There are four possible parity settings: Odd, Even, None, and Ignore.

Odd	The port expects to receive data frames with an odd number of logical
	1’s per byte. The printer transmits XOFF and XON with odd parity. If the
	printer detects a parity error, the port sends X'5F' to the printer instead
	of the character sent by the host system.
Even	The port expects to receive data frames with an even number of logical
	1’s per byte. The port transmits XOFF and XON with even parity. If the
	port detects a parity error, the port sends an inverted question mark to
	the printer instead of the character sent by the host system.
None	The port expects no parity bit when it receives data. The port transmits
	XON and XOFF without parity bits.
Ignore	The port expects a parity bit when the port receives a data frame. The
	port ignores the parity bit. The port uses even parity when it transmits
	XON and XOFF.

Some printers post a 54 Standard Serial Error or a 54 Serial Option x Error (x represents the number of the serial port) the first time they detect a transmission error (parity, overrun, or framing). The 54 Standard Serial Error or the 54 Serial Option x Error can be reset from your printer operator panel or through MarkVision Professional. Refer to your printer user documentation for more information.

If repeated serial errors occur, power the printer off and back on to restore proper serial operation.

Data Flow Control Protocol

One data flow control protocol is available: XON/XOFF with programmable polarity. Refer to your printer user documentation for more information about selecting the protocol from your printer operator panel or through MarkVision Professional.