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HP-IS Fundamentals
Command Mode and Data Mode
Command Mode and Data Mode
There are two modes of communication on
HP-IB:
Command mode and
Data mode.
In
Command Mode,
information transmitted across the eight data lines is
interpreted as talk or listen addresses, or universal address or unaddress
commands (explained later). In this mode, only seven of the data lines are
used. Some devices use the eighth line as a parity check for certain
protocols.
In
Data Mode,
any eight-bit value can be transmitted. The
HP-lB
can
therefore be used for transmission of binary data as well as ASCn
characters.
The three-line handshake scheme has several advantages. First, data transfer
is synchronous-the data rate is usually limited by the speed of the devices
actively involved in the transfer. A second. related advantage is that devices
with different
110
speeds can be interconnected without the need for other
synchronization mechanisms. Also, multiple devices can be addressed
concurrently.
30
A
Summary of Contents for HP 82335
Page 2: ...HP 82335 82340 and 82341 HP IB Interface Installation Guide for HP 110 Libraries ...
Page 3: ...11 ...
Page 12: ...1 Introduction ...
Page 17: ...Introduction Environmental Specifications Notes 8 Chapter ...
Page 18: ...2 Hardware Installation ...
Page 34: ...A l HP IB Fundamentals ...
Page 48: ...B Using Fast Talker Mode with the HP 82341 ...
Page 50: ...Index ...
Page 53: ...Index 44 ...