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Chapter 14 RS-232 And RS-422 Serial Interfaces
RS-232 And RS-422 Serial Interface Error Handling
Parity Error Handling. Parity error checking is a configuration option
selected from the operator panel.
With odd or even parity checking selected, a character with a parity error is
replaced with a question mark (?) character.
When parity checking is not selected (“NONE” on the operator panel), parity
errors are ignored and the characters are printed as received.
Framing Error Handling. Framing error checking is always in effect for the
serial interface.
When a framing error occurs, an exclamation point (!) is printed. If 20
successive errors are received, a line feed is added to force printing to occur.
Overrun Error Handling. Overrun error checking is always in effect for the
serial interface.
When a data overrun error occurs, an asterisk (*) is printed. If 20 successive
errors are received, a line feed is added to force printing to occur.
RS-232 And RS-422 Serial Interface Configuration
By using the control panel, you can verify and change several interface
parameters in order to meet specific application requirements.
Refer to “Serial Submenu” on page 114 for RS-232 and RS-422 parameter
descriptions and information on selecting values for the following parameters:
RS-232 and RS-422
• Baud Rate (data rate selected from the operator panel)
• Data Bits (7 or 8 Bits)
• Stop Bits (1 or 2 Bits)
• Parity (None, Odd, Even, Mark or Sense)
RS-232 only
• Data Terminal Ready logic
• Request to Send logic
Some application programs require a unique configuration. If the printer is not
working properly with the configuration you selected, contact a Hewlett-
Packard Customer Service Engineer.
Note All serial errors are treated as faults that require operator intervention.
