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5.7.7 Programming Using VISA Drivers
5.7.7.1 VISA Description
In the test and measurement industry, Virtual Instrument Software Architecture (VISA) is a popular
framework that includes hardware drivers, configuration utilities and connection managers.
Varieties of communication busses are supported. VISA drivers are available from several
instrument vendors.
Any programming language that supports Windows COM or DLL libraries can call the VISA
functions.
5.7.7.2 VXI-11 Compatibility
VXI-11 is a protocol that allows communications between a computer port and an instrument. VISA
is built upon the VXI-11 specification. The Power Supply is compatible with the VXI-11
protocols:
•
VXI–11 Device_link Open link to an instrument
•
VXI–11 Device_write Write text to an instrument
•
VXI–11 Device_read Read text from an instrument
•
VXI–11 Destroy_link Close link to an instrument
5.7.7.3 Opening the VISA Connection
Test and automation programs may easily be written if they use the VISA libraries. The supported
VISA functions include Open, Read, Write and Close.
A VISA resource descriptor is used to describe a particular supply. For the Power Supply,
the descriptors are found on the supply’s Home web page. The VISA resource may use the
supply’s IP address or hostname.
Example
of VISA resource descriptors are:
Format: TCPIP[board]::IP address/Host Name[::LAN device name][::INSTR]
[board] is the LAN card number, zero is optional
[::LAN device name] is by default “inst0”
[::INSTR] is optional
Examples:
TCPIP::10.225.26.60::inst0::INSTR
5.7.7.4 Communicating Using VISA
The VISA Write function sends SCPI commands to the Power Supply. The VISA read function
reads the response returned from the SCPI query.
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