The Centronics Interface - HP 1660CS-Series User Manual

The RS-232-C, HP-IB, and Centronics Interfaces

The Centronics interface

Stop Bits
Stop Bits are used to identify the end of a character. The number of Stop Bits
must be the same for the controller as for the logic analyzer.
Parity
The parity bit detects errors as incoming characters are received. If the parity
bit does not match the expected value, the character was incorrectly
received. The action taken when an error is detected depends on the
interface and the device program configuration.
Parity is determined by the requirements of the system. The parity bit may
be included or omitted from each character by enabling or disabling the
parity function.
Data Bits
Data Bits are the number of bits used to represent the binary code of a
character. The HP 1660CS-series logic analyzers support 8-bit binary code.
Protocol
Protocol governs the flow of data between the instrument and the external
device. It can be controlled either by the hardware, in which case you select
None in the RS-232-C Settings pop-up, or by the software, in which case you
select Xon/Xoff. Xon/Xoff stands for Transmit On/Transmit Off.
With less than a 5-wire interface, selecting None does not allow the sending
or receiving device to control how fast the data is being sent, increasing the
possibility of missing data. With a full 5-wire interface, selecting None allows
a hardware handshake to occur. With a hardware handshake, hardware
signals control data flow. The HP 13242G cable allows the logic analyzer to
support hardware handshake.
The Centronics interface
The Centronics interface is an industry-standard parallel printer interface. It
can only be used as a printer interface, and is not available to the controller.
There are no Centronics-specific settings; page and line length are set in the
Printer Settings menu.
See Also
Chapter 2, "Connecting Peripherals," for more information on setting up the
parallel printer port.
7-28