standard commands for programmable instruments (SCPI)

Standard Commands for Programmable Instruments (SCPI) is a command language used to program and control electronic test and measurement equipment. SCPI was designed in the 1990s and standardized as part of IEEE 488. SCPI defines the syntax, command structure, and data format for controlling programmable measurement and test equipment. It uses common in ASCII commands such as CONFigure and MEASure that can be used in all programmable measurement instruments.

SCPI commands can be entered in short and long form, for example frequency as FREQ or FREQuency. In addition, there are general commands, Common Commands, subsystem commands, Subsystem Commands, readout commands, Query Commands and parameter commands, Parameter Commands.

The Common Commands are used for interface control and not for encoder control. These commands start with a *, they can be used to reset an encoder, for example. Example: WRITE TEXT "* RST". The subsystem commands are used to support the encoder functions. They work with a root directory with main groups and subgroups. The Query Commands are used for reading the measured values. They end with a ?, for example: FREQ: CW? And Parameter Commands are used to change measurement parameters.

The SCPI command language is independent of the bus structure and can be used with the General Purpose Interface Bus( GPIB), with IEEE 488, but also with RS232-C, the USB interface, the LAN Extensions for Instrumentation( LXI) or the VXI bus.