Instrument Driver
Encyclopedia
An Instrument Driver, in the context of Test & Measurement (T&M) application development, is a set of software routines, which simplifies remote instrument control
. The specification of instrument drivers is defined by the IVI Foundation.
Due to this definition an I/O
abstraction via Virtual Instrument Software Architecture
(VISA) is done. The VISA hardware abstraction layer provides an interface independent communication channel to T&M instruments. Furthermore an encapsulation of the SCPI-commands is done by instrument drivers. Whereas the SCPI command is a ASCII
-based set of commands for reading and writing instrument settings and measurement data. This allows an abstract way of programming in various programming languages, compared to programming remote control applications with SCPI commands only. An instrument driver is usually characterized by a well defined API
.
and GPIB instruments. As part of unifying process also VXIplug&play instrument drivers where defined.
driver architecture is based on the Microsoft Component Object Model
. The IVI-C drivers are based on C programming language
shared components (shared libraries). Beside this, the IVI.NET
driver architecture was specified in 2010. The IVI.NET drivers are based on the .NET
framework.
commands by providing a well defined API. The IVI and VXIplug&play instrument drivers are utilizing the VISA as hardware abstraction layer thus interface hardware independent applications can be developed.
library allows to connect test & measurement equipment via various hardware interfaces. Following interfaces are available:
.
Instrument control
Instrument control consists of connecting a desktop instrument to a computer and taking measurements.-History:In the late 1960s the first bus used for communication was developed by Hewlett-Packard and was called HP-IB...
. The specification of instrument drivers is defined by the IVI Foundation.
Due to this definition an I/O
Input/output
In computing, input/output, or I/O, refers to the communication between an information processing system , and the outside world, possibly a human, or another information processing system. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it...
abstraction via Virtual Instrument Software Architecture
Virtual Instrument Software Architecture
Virtual Instrument Software Architecture, commonly known as VISA, is a widely used I/O API in the test and measurement industry for communicating with instruments from a PC...
(VISA) is done. The VISA hardware abstraction layer provides an interface independent communication channel to T&M instruments. Furthermore an encapsulation of the SCPI-commands is done by instrument drivers. Whereas the SCPI command is a ASCII
ASCII
The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
-based set of commands for reading and writing instrument settings and measurement data. This allows an abstract way of programming in various programming languages, compared to programming remote control applications with SCPI commands only. An instrument driver is usually characterized by a well defined API
Application programming interface
An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...
.
Standards
For instrument drivers the VXIplug&play Alliance (became part of the IVI Foundation in 2002) defined a common structure for so called 'VXIplay&play instrument drivers'. As designed successor of the VXIplug&play standard, the IVI Foundation defined a new generation of instrument drivers, these so called IVI (Interchangeable Virtual Instrumentation) drivers are currently defined in three different architectures.VXIplug&play Instrument Driver
The VXIplug&play Systems Alliance was founded 1993 with the aim of unifying VXI hard- and software to achieve 'plug&play' interoperability for VXIVXI
The VXI bus architecture is an open standard platform for automated test based upon VMEbus. VXI stands for VME eXtensions for Instrumentation, defining additional bus lines for timing and triggering as well as mechanical requirements and standard protocols for configuration, message-based...
and GPIB instruments. As part of unifying process also VXIplug&play instrument drivers where defined.
IVI Instrument Drivers
The IVI instrument driver specification is a further development of the VXIplug&play driver standard. This specification intends to overcome the VXIplug&play drawbacks. The IVI-COMComponent Object Model
Component Object Model is a binary-interface standard for software componentry introduced by Microsoft in 1993. It is used to enable interprocess communication and dynamic object creation in a large range of programming languages...
driver architecture is based on the Microsoft Component Object Model
Component Object Model
Component Object Model is a binary-interface standard for software componentry introduced by Microsoft in 1993. It is used to enable interprocess communication and dynamic object creation in a large range of programming languages...
. The IVI-C drivers are based on C programming language
C (programming language)
C is a general-purpose computer programming language developed between 1969 and 1973 by Dennis Ritchie at the Bell Telephone Laboratories for use with the Unix operating system....
shared components (shared libraries). Beside this, the IVI.NET
.NET Framework
The .NET Framework is a software framework that runs primarily on Microsoft Windows. It includes a large library and supports several programming languages which allows language interoperability...
driver architecture was specified in 2010. The IVI.NET drivers are based on the .NET
.NET Framework
The .NET Framework is a software framework that runs primarily on Microsoft Windows. It includes a large library and supports several programming languages which allows language interoperability...
framework.
Remote Control of Instrumentation
The development time needed for remote control applications for instrumentation can be decreased due to the usage of instrument drivers. Instrument drivers try to overcome the difficulty of string formatting when using SCPIStandard Commands for Programmable Instrumentation
The Standard Commands for Programmable Instruments defines a standard for syntax and commands to use in controlling programmable test and measurement devices.- Overview :...
commands by providing a well defined API. The IVI and VXIplug&play instrument drivers are utilizing the VISA as hardware abstraction layer thus interface hardware independent applications can be developed.
I/O Hardware Abstraction Layer VISA
The VISAVirtual Instrument Software Architecture
Virtual Instrument Software Architecture, commonly known as VISA, is a widely used I/O API in the test and measurement industry for communicating with instruments from a PC...
library allows to connect test & measurement equipment via various hardware interfaces. Following interfaces are available:
- Serial PortSerial portIn computing, a serial port is a serial communication physical interface through which information transfers in or out one bit at a time...
- GPIB/IEEE-488IEEE-488IEEE-488 is a short-range digital communications bus specification. It was created for use with automated test equipment in the late 1960s, and is still in use for that purpose. IEEE-488 was created as HP-IB , and is commonly called GPIB...
- VXI-11 (over TCPIP)
- USB488/USBTMC (USB Test & Measurement), USB Test & Measurement Class Specification
- HiSLIP (over TCPIP).
LXI
The LAN eXtensions for Instrumentation (LXI) standard defines the communications protocols for controlling the arming, triggering and event functionality of LXI instrumentation using EthernetEthernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
.
See also
- Instrument controlInstrument controlInstrument control consists of connecting a desktop instrument to a computer and taking measurements.-History:In the late 1960s the first bus used for communication was developed by Hewlett-Packard and was called HP-IB...
- Standard Commands for Programmable Instruments
- AutomationAutomationAutomation is the use of control systems and information technologies to reduce the need for human work in the production of goods and services. In the scope of industrialization, automation is a step beyond mechanization...
- IEEE-488IEEE-488IEEE-488 is a short-range digital communications bus specification. It was created for use with automated test equipment in the late 1960s, and is still in use for that purpose. IEEE-488 was created as HP-IB , and is commonly called GPIB...
- VISAVirtual Instrument Software ArchitectureVirtual Instrument Software Architecture, commonly known as VISA, is a widely used I/O API in the test and measurement industry for communicating with instruments from a PC...
- LabVIEWLabVIEWLabVIEW is a system design platform and development environment for a visual programming language from National Instruments. LabVIEW provides engineers and scientists with the tools needed to create and deploy measurement and control systems.The graphical language is named "G"...
- LabWindows
- Agilent VEEAgilent VEEAgilent VEE is a graphical dataflow programming software development environment from Agilent Technologies for automated test, measurement, data analysis and reporting. VEE originally stood for Visual Engineering Environment and developed by HP designated as HP VEE; it has since been officially...
- LAN eXtensions for Instrumentation