SCPI Explained What is SCPI?

Before SCPI

In the early days of programmable instruments, each manufacturer created their own language for controlling their equipment remotely. Few manufacturers would share the same language or syntax. Even equipment made by the same manufacturer often used a completely different language from their other equipment.

As programmable instruments became more powerful, so the control languages had to become more complex. For a customer building integrated testing systems and control software, the overhead of learning how to control each piece of equipment had become a major problem.

The SCPI Consortium

The SCPI (Standard Commands for Programmable Instruments) Consortium evolved to standardize the control language used between programmable instruments. Its aim is to promote a common language and syntax suitable for all programmable instruments. The SCPI Consortium meet once a year to consider modifications to the SCPI Standard. The SCPI Standard is downloadable free of charge - see the links.

Today, SCPI is supported by most of the manufacturers of programmable instruments including Agilent (HP), Tektronix, Keithley, Fluke, and Racal.

But what is SCPI?

The SCPI Standard specifies the command structure and syntax to be used for controlling programmable instruments via a communications link, such as GPIB, RS232, USB, VXIbus etc. SCPI also includes standard command sets for different “classes” of instruments, e.g. electrical sources, and measurement devices such as DMMs and oscilloscopes.

SCPI commands are in human-readable ASCII format. Because of this, SCPI commands can be sent easily using any programming language including C, C++, Visual Basic, etc. In addition, SCPI is supported by Test Application Software such as Lab View and HP VEE.

SCPI Commands >>