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1260-145 User Manual
Racal Instruments
2003
Module Operation 3-3
Figure 3-1, Message-Based Mode of Operation
In
the
register-based
mode, the user writes directly to the port
registers on the 1260-145 module. The 1260-01T command
module does not monitor these operations, and does not keep
track of the port states on the 1260-145 module in this mode.
A conceptual view of the register-based mode is shown in
Figure 3-2
below.
Figure 3-2, Register-Based Mode of Operation
Since the 1260-01T switch controller does not keep track of port
and control register states during the register-based mode, it is
advisable to use
either
the message-based or the register-based
mode consistently, and use the chosen mode exclusively
throughout the application program.
In general, the message-based mode of operation is easier to use
with utility software such as the National Instruments VXI
Interactive Control (VIC) program. The message-based mode
allows the user to send ASCII text commands to the 1260-01T and
to read replies from the 1260-01T. In addition, some features, such
as scan lists, are available only in the message-based mode.
The register-based mode provides faster and more direct control of
the 1260-145. In this mode, direct port and control register
operations are processed in less than 9 microseconds, not
counting software overhead inherent in I/O libraries such as VISA.
For further information about message-based vs. register-based
PC (MXI)
1260-01T
1260-145
VXIbus
"CLOSE (@1(0))"
Write to A24 Address {base a
0x401}
PC (MXI)
1260-145
Write to A24 Address {base a 0x401}
Summary of Contents for 1260 VXI
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