Printronix P5005B, User Manual, Page: 247 / 366

Serial Submenu
247
Interface Type
This parameter allows you to select either the RS-232 or RS-422
serial port interface.
Data Protocol
You can select one of the following serial interface protocols to
meet the host interface requirements.
•
XON / XOFF (default). The printer controls the flow of
communication from the host by turning the transmission on
and off. In some situations, such as when the buffer is full or the
timing of signals is too slow or too fast, the printer will tell the
host to stop transmission by sending an XOFF character. An
XOFF character is sent when the number of empty bytes in the
buffer is less than or equal to 25 percent of the buffer size. If the
host keeps sending data after an XOFF is sent, the printer
firmware will continue to send an XOFF for every 16 characters
received. When cleared, the printer will resume receiving data
(XON). The data does not have any End of Text codes;
XON / XOFF is a non-block protocol.
•
ETX / ACK . End of Text / Acknowledge. The host controls the
flow of communication to the printer by sending a block of data
and ending the block with an End of Text (ETX) signal. When
the printer receives the ETX signal, it will acknowledge the
ETX, thereby acknowledging it has received the entire block of
data.
•
ACK / NAK . ACK means acknowledge; the device
acknowledges it has accepted a transmission. NAK means
negative acknowledge; the device did not receive the
transmission.