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Jump-start
programmers with source code examples. Vscan provides the active
connection between your Vsystem real-time database
and I/0 hardware. This application builds the list
of input channels to be scanned from the real-time databases, scans the
hardware at a rate you specify, and places the new values into the database. Vscan uses the I/O handler in the Vaccess database to read or write the I/O registers. I/O
handlers are normally used when the I/O register is available directly to the
computer for reading and writing, that is there is
no communication protocol overhead. Where such protocols are used, such as
TCP/IP, then a scanner should be used. A scanner is a separate process that
makes block transfers to optimize the data throughput through the connection
to the I/O registers in the hardware.
Vscan software is provided as one of
many Vsystem examples in source-code form. Access
to this source code enables you to customize Vscan
to meet the specific demands of your projects.
With Vscan you can
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Maintain fast, slow, and no-scan queues using the interest counts and
I/O error bits.
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Customize scanner development--Vscan is
distributed in source and executable form to assist you.
Updated Jan
5, 2010
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