tclvisa is a standard Tcl extension providing a binding to Virtual Instrument Software Architecture (VISA ) API. It allows to use VISA functionality from regular Tcl scripts via set of commands. Most of the commands have similar names and are intuitive to use for the one who knows VISA API. For example, Tcl command [visa::open]visa::open is a front-end for viOpen VISA function. The specifications of VISA can be found here: http://www.ivifoundation.org/specifications/default.aspx.
As an extention tclvisa follows conventions of Tcl Extension Architecture (TEA). It is loaded dynamically into Tcl shell or Tcl-based application on demand. Please refer to TEA documentations for details: http://www.tcl.tk/doc/tea/.
For detailed tclvisa documentation click here.