HP LQH-HW 3ULQWHUV manual RS-232 And RS-422 Serial Interface Error Handling, RS-232 and RS-422

Chapter 14 RS-232 And RS-422 Serial Interfaces

RS-232 And RS-422 Serial Interface Error Handling

Note All serial errors are treated as faults that require operator intervention.

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.

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