Lexmark 21Z0294 Technical Reference - Page 316

8-14 Interfaces Serial Data Frame Considerations (RS-232C) The computer sends serial data in data frames (also known as packets). You can create 10-bit, 11-bit, and 12-bit data frames and set the serial data transfer parameter so that each data frame contains 7 or 8 data bits. However, your printer is an 8-bit printer; characters, controls, and all points addressable (APA) graphics need 8 bits of data. If you select 7-bit data transfer, some unexpected characters might print. Data Transmission The list of acceptable data transfer rates (in bits per second) can be accessed from the printer control panel or through MarkVision Professional. See your printer documentation for more information. Data Bits The printer sends or receives 7 or 8 data bits in each transmission frame, depending on which one is selected. Start and Stop Bits The printer receives data with 1 start bit and either 1 or 2 stop bits. The printer always sends 1 start and 2 stop bits. Parity There are four possible parity settings: Odd, Even, None, and Ignore. Odd Even None Ignore 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. 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. The port expects no parity bit when it receives data. The port transmits XON and XOFF without parity bits. 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.