Section 2: General operation
Models 707B and 708B Switching Matrix Reference Manual
2-30
707B-901-01 Rev. B / January 2015
Connecting multiple USB instruments to the computer
The most convenient way to connect USB instrumentation to the computer is to plug a USB cable
directly from the instrument to the computer. If you have more than one USB instrument or have other
USB devices, such as printers, keyboards, and mice, you might not have enough USB connectors on
the computer.
To gain more ports, you can use a USB hub or add more USB controller cards if you have available
PCI or PCI Express slots.
There are two types of USB hubs that you can use with Model 707B or 708B:
•
Bus powered
: This type of hub draws its power from the USB bus and can only supply 100 mA
(USB 2.0) per port.
•
Self powered
: This type of hub has an external power supply and can supply up to 500 mA per port
(USB 2.0).
USB VISA identifiers
The USB identifiers to communicate with your Keithley instrument using VISA are:
•
707B:
USB0::0x05E6::0x707B::[serial number]::INSTR
•
708B:
USB0::0x05E6::0x708B::[serial number]::INSTR
Where:
•
USB0: USB interface
•
0x05e6: The Keithley vendor ID (assigned to Keithley Instruments by the USB Implementers Forum,
Inc.)
•
707B or 708B: Instrument model number
•
[serial number]: The serial number of the instrument (the serial number is also on the rear panel)
•
INSTR: Use the USBTMC protocol
GPIB setup
This section contains information about GPIB standards, connections, and address selection.
The GPIB connector is optional and may not be present on your instrument.
GPIB standards
The GPIB is the IEEE-488 instrumentation data bus, which uses hardware and programming
standards originally adopted by the Institute of Electrical and Electronic Engineers (IEEE) in 1975.
The instrument is IEEE Std 488.1 compliant and supports IEEE Std 488.2 common commands and
status model topology.
