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Number 2875
Application Note Converting a Series 2700 SCPI Application
Series to a Series 3700 System Switch/
Multimeter System Script Application
Introduction tain command subsystems that control particular instrument
functions and settings.
For many years, instrument manufacturers have used "Standard
Commands for Programmable Instrumentation" or SCPI to con- The SCPI Instrument Model is divided among the SCPI com-
trol programmable test and measurement devices in instrumen- mand subsystems. In the case of the Series 2700, the command
tation systems. SCPI provides a uniform and consistent language subsystems are broken down into these categories:
for the control of test and measurement instruments. The same 1. Signal-Oriented Measurement: Commands used to acquire
commands and responses control corresponding instrument readings.
functions in SCPI equipment, regardless of the manufacturer or
2. Calculate: Used for math expressions, limit testing, and
the instrument type.
statistics.
By design, Keithley's new Series 3700 System Switch/ 3. Display: Controls the display of the Integra instruments.
Multimeter instrument does not use SCPI commands. The plat-
form instead uses an internal Test Script Processor (TSP) to pro- 4. Format: Selects the data format for transferring readings
cess and run programs called "scripts." The migration to TSP was over the bus.
to address the more demanding system throughput requirements 5. Route: Controls front/rear inputs or switching.
common to today's systems. Communication to any TSP instru- 6. Sense: Configures and controls the measurement
ment is the same as interfacing to a conventional instrument functions.
using commercially available software applications and appli-
7. Status: Controls the status registers.
cation development environment. The user simply sends text
strings containing either TSL or ICL commands to the instrument 8. System: Contains miscellaneous commands for instrument
using the communication interface. Although Keithley provides setup.
an application suite called Test Script Builder (TSB), it is not 9. Trace: Configures and controls data storage into the
intended as the only tool to communicate to the instrument, nor buffer.
does not replace commercially available software applications. 10. Trigger: Configures the Trigger Model.
TSB is a basic tool available to use to develop scripts for TSP
11. Unit: Configure the query the displayed measurement
instruments.
units
A script is a collection of instrument control commands and/
or program statements. Program statements control script execu- The TSP Instrument Model
tion and provide facilities such as variables, functions, branching, Test Script Language (TSL) is the language of the Series 3700. ICL
and loop control. TSB is a programming interface in which users is a group of predefined functions and variables that are used to
can create powerful, high speed, multi-channel tests to down- control the instrument. They are the instrument commands that
load into either the unit's volatile or nonvolatile memory. Using are equivalent to SCPI commands in the SCPI instruments. The
the downloaded script, the unit controls itself, independent following command sets apply to the Series 3700:
of the system's host controller. This capability can free up the 1. Beeper: Commands used to control the built-in beeper.
system controller to interface with other equipment in the rack
more frequently, thereby increasing the overall system through- 2. Bit: Used to perform logic operations on one or two
put. Furthermore, the Series 3700 has very deep memory; pro- numbers.
gram memory can hold 50,000 lines of code and data memory 3. Delay: Used to control read/write and trigger operations
can store at least 450,000 readings. for the digital I/O port.
This application note compares the Series 2700 SCPI-based 4. Digital I/O: Selects the data format for transferring
applications with the new Series 3700 scripting approach. readings over the bus.
5. Display: Used to control display messaging on the front
Comparing SCPI to ICL Commands and Scripts panel of the Model 3700.
The SCPI Instrument Model 6. Error Queue: Used to read the entries in the error/event
Some measurements require direct control over an instrument's queue.
hardware. To provide this control, SCPI-based instruments con- 7. Exit: Used to terminate a script that is presently running.
8. Format: Used for data printed with the printnumber and Example 1. A complete comparison of the Series 3700 TSP lan-
printbuffer commands. guage commands versus the comparable SCPI commands for the
9. GPIB: Used to set the GPIB address. Series 2700 is listed in Table 1.
10. LocalNode: Used to set the power line frequency, control Example 1: Volts Measurement/Simple Scan Channels 1