Usb Communications - Keithley 2601B Reference Manual

Section 2: General operation Series 2600B System SourceMeter® Instrument Reference Manual

USB communications

To use the rear-panel USB connection, you must have the Virtual Instrument Software Architecture
(VISA) layer on the host computer. See How to install the Keithley I/O Layer (on page 2-102) for more
information.
VISA contains a USB class driver for the USB Test and Measurement Class (USBTMC) protocol
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which, once installed, allows the Microsoft Windows operating system to recognize the instrument.
When a USB device that implements the USBTMC or USBTMC-USB488 protocol is plugged into the
computer, the VISA driver automatically detects the device. It is important to note that only USBTMC
and USBTMC-USB488 devices are automatically recognized by the VISA driver. Other USB devices,
such as printers, scanners, and storage devices, are not recognized.
In this section, "USB instruments" refers to devices that implement the USBTMC or
USBTMC-USB488 protocol.
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The full version of National Instruments (NI ) VISA provides a utility to create a USB driver for any
other kind of USB device that you want to communicate with VISA. For more information, see the NI
VISA website (see National Instruments VISA site - http://www.ni.com).
Communicate with the instrument
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To communicate with the USB instrument, you need to use NI-VISA . VISA requires a resource
string in the following format to connect to the correct USB instrument:
USB[board]::manufacturer ID::model code::serial number[::USB interface number][::INSTR]
This requires that you determine the parameters. You can gather this information by running a utility
that automatically detects all instruments connected to the computer.
If you installed the Keithley I/O Layer, the Keithley Configuration Panel is available from the
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Microsoft Windows Start menu in the Keithley Instruments menu.
To use the Keithley Configuration Panel to determine the VISA resource string:
1. Start the Keithley Configuration Panel. The Select Operation dialog box is displayed.
2. Select Add.
2-92 2600BS-901-01 Rev. B / May 2013