Vscan

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

·         Maintain fast, slow, and no-scan queues using the interest counts and I/O error bits.

·         Customize scanner development--Vscan is distributed in source and executable form to assist you.

Updated Jan 5, 2010