Printronix P3000 Series manual RS-232 Serial Interface Configuration

ACK/NAK – With ACK/NAK protocol selected, the printer responds as described for ETX/ACK pro- tocol except the printer monitors the received data for parity error. If a parity error is detected, a NAK character is transmitted to the host upon receipt of the ETX character. The host is expected to repeat the data transmission.

RS–232 INTERFACE ERROR – With an odd or even parity check in effect, the detected character error shall be replaced with a question mark (?). If a parity error is detected, a NAK character (hex 15) is transmitted to the host when the ACK/NAK protocol is selected. When parity is not checked, parity errors are ignored and the characters are printed as received. Parity checking is a configuration option selected from the control panel. When a framing error occurs, an exclamation point (!) prints. When a data overrun error occurs, an asterisk (*) prints. After 20 successive errors have been received, a line feed is added which forces printing to occur.

RS–232 Serial Interface Configuration

The printer is configured at the factory. However, the configuration is also user selectable. The follow- ing configuration parameters can be verified or changed as necessary to meet specific application re- quirements:

•Data Protocol of hardware (DTR, Reverse Channel, or RTS), or X–ON/X–OFF, ACK/ NAK or ETX/ACK

•Data Rate (baud rate selected from the control panel)

•Data Word Length (7 or 8 bits)

•Stop Bits (1 or 2 bits)

•Parity (odd, even, or none)

•Bit 8 Function (font select, PI line, or ignore)

•CD and CTS signal (enable or disable)

•DSR signal (enable or disable)

•Data Terminal Ready response logic

•Request to Send response logic

•Reverse Channel response logic

These parameters are displayed under the Application Compatibility/Host Interface/Serial RS–232 submenu selectable from the control panel. Refer to the Control Panel Configuration diagram in the Configuration chapter for detailed information on selecting the various parameter values.

NOTE: Do not use the bit 8 function to set the PI line if the host does not use it for paper control; rapid paper slewing may occur.

7–12 Interfaces