Series 2600B System SourceMeter® Instrument Reference Manual
Section 2: General operation
2600BS-901-01 Rev. C / August 2016
2-91
Output queue
Response messages, such as those generated from print commands, are placed in the output queue.
All remote command interfaces share the same output queue.
The output queue sets the message available (MAV) bit in the status model.
The data in the output queue is cleared by the
*CLS
command.
USB communications
To use the rear-panel USB port, 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 that,
once installed, allows the Microsoft
®
Windows
®
operating system to recognize the instrument.
When you connect a USB device that implements the USBTMC or USBTMC-USB488 protocol to the
computer, the VISA driver automatically detects the device. Note that the VISA driver only
automatically recognizes USBTMC and USBTMC-USB488 devices. It does not recognize other USB
devices, such as printers, scanners, and storage devices.
In this section, "USB instruments" refers to devices that implement the USBTMC or
USBTMC-USB488 protocol.
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
National Instruments VISA site
(see National Instruments VISA site -
http://www.ni.com
).
Communicate with the instrument
To communicate with the USB device, you need to use NI-VISA
TM
. 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
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
.
