Printronix P3000 Series - Manual (Page 168)

Interfaces 7–12
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.