HP manual Driver Types

Driver developers also provide wrapper interfaces optimized for specific development environments. The wrapper functions as an adapter between an ADE and a driver not designed for that ADE. It enables the ADE to use technologies for which no native implementation exists. In Chapter 6, IVI with MATLAB, for example, generating an instrument wrapper is a key step in creating the program.

Driver Types

The schematic on the next page shows the three basic types of drivers: Both IVI- COM and IVI-C use Custom and Class Compliant Drivers, but Class Drivers are unique to IVI-C. Usually, you only need to be concerned about the type of driver if you want to enable interchangeability. To understand the differences among them, you first need to understand the various capabilities these drivers support:

Inherent capabilities: capabilities required by the IVI Foundation, such as instrument simulation, state-caching, interchangeability checking, and range checking, as well as commands, such as Initialize, Reset, and Close. Some capabilities are required for all drivers, but others are optional.

Base class capabilities: capabilities identified by an IVI Foundation working group as common among the majority of instruments in a class. In the DMM class, for example, base capabilities include performing a DC voltage or current measurement.

Class extension capabilities: capabilities identified by an IVI Foundation working group as less common but still supported by multiple instruments within a class. In the DMM class, for example, class extension capabilities include temperature measurement.

Instrument-specific or vendor-specific capabilities: capabilities not standardized by IVI and unique to a manufacturer’s specific instrument. In the DMM class, for example, this might be a measurement that uses a thermocouple to sense the temperature.

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