Standard Commands For Programmable Instruments

What Does Standard Commands For Programmable Instruments Mean?

Standard Commands for Programmable Instrumentation (SCPI) defines a standard intended for instrumentation control. The SCPI describes a language that is useful for controlling test instruments. SCPI offers a standard syntax, data interchange format and command structure.

The key objective of SCPI is to minimize the development time of an automatic test equipment (ATE) program. The objective is accomplished through providing a reliable programming environment for data usage and instrument control. This reliable programming environment is gained using defined data formats, program messages and instrument responses across every SCPI equipment irrespective of the designer.

SCPI is usually pronounced "skippy."

Techopedia Explains Standard Commands For Programmable Instruments

SCPI devices are incredibly flexible in accepting an array of parameter and command formats, which makes them simpler to program. The responses from the instrument that is delivered back to the controller could be either status or data information. The response format of a specific query of an SCPI instrument is well defined, and it cuts down the programming efforts needed to comprehend the status as well as the instrument data information.

The programming consistency of SCPI is both horizontal and vertical. Vertical programming consistency specifies program messages inside an instrument class, whereas horizontal consistency uses the same command to manage similar functions all over the instrument classes.

SCPI has the ability to provide many different instrument control levels. Standard measure commands deliver users with quick and easy commands over SCPI instrumentation, whereas more comprehensive commands offer conventional instrument control.

ATE systems programmers can benefit from SCPI significantly. SCPI reduces the time required for ATE systems programmers to learn how to program new SCPI equipment after programming their initial SCPI equipment. SCPI is beneficial for programmers who:

• Use programming languages like FORTRAN, C, etc., to deliver commands to instruments
• Install instrument device drivers for ATE program generators
• Install instrument device drivers for software instrument front panels

SCPI describes parameters, instrument commands, statuses and data. SCPI is not a programming language, application package or software aimed at instrument front panel control.

SCPI is built to be layered over the hardware-independent part of IEEE 488.2. Moreover, SCPI works well with controller-to-instrument interfaces, including RS-232C, IEEE 488.1, VXIbus, etc.