Choose the Correct Interface for Your Instruments

You may have a choice of several different physical interfaces with which to connect your instrument to your PC. This topic will give you some guidelines to help with that decision. If you are constructing a large or complex test system, or if your test system will be used for a long time, you will want to make this decision carefully.

First, determine the interfaces that are available to you on each side of the connection (instrument and PC). Not all interfaces are available on all instruments. PCs typically have USB, LAN, and a limited number of serial interfaces available, but require the addition of a card (such as the Keysight 82350 PCI GPIB Card) to support GPIB.

Adaptor products are available to connect a PC to GPIB instruments using either the PC's USB interface (Keysight 82357 USB/GPIB Interface Converter) or its LAN interface (Keysight E5810B LAN/GPIB/USB Gateway). These products provide convenient and powerful ways for you to take advantage of PC-standard I/O with a large range of instruments from many manufacturers.

Supported Interface Types

The interfaces that can be used with Keysight IO Libraries Suite are:

• LAN interfaces
• GPIB interfaces
• USB interfaces

 

LAN Interfaces

A LAN (TCP/IP) interface is a logical collection of properties that can apply to remote interfaces and instruments, including:

• Instruments with direct TCP/IP connections

A LAN interface does not directly represent physical devices. Any number of physical devices may be auto-discovered or manually added on a single LAN interface, in which case the properties associated with that interface will be applied to all associated devices.

The default LAN interface is TCPIP0. If you want to change the interface properties (such as timeouts) for all LAN instruments, then edit the LAN interface TCPIP0. If you want to have two or more groups of instruments with different interface properties, add a new LAN interface, and then add each instrument, specifying the interface whose properties you wish to apply to that instrument.

Note that all auto-discovered instruments are assigned the interface TCPIP0; if you want them to use a different interface, you must manually add them. (If you manually add an instrument that is already auto-discovered, it will have two VISA addresses, and you can use the one you prefer.)

You can configure multiple LAN interfaces on your PC, each having unique interface properties.

Connecting Instruments via LAN

A local area network (LAN, also known as Ethernet) provides instrument connectivity over distances and allows sharing of instruments among multiple users and multiple PCs. Ethernet LANs are almost universally available; they support data rates of 10 to 1000 megabits/second, and they use inexpensive cables and connectors. Many instruments have LAN interfaces built in; for those that do not, you can use the KeysightE5810B LAN/GPIB/USB Gateway. LAN is a recommended method to connect instruments together in applications such as new test systems.

You can connect your instruments to a private LAN or to a site LAN.

• A private LAN is set up specifically for your use in connecting your instruments. Typically, you will be the administrator of the private LAN, and you will control connections, cabling, and addressing. Your PC and all instruments are connected via a networking switch or router that isolates them from your site LAN. You can think of a private LAN as just another type of bus for your test system, like GPIB or USB; the private LAN is used only by your test system. You should use a private LAN if you want total control of your network and instruments, or if it is important that your test system achieve maximum throughput.



• Your site LAN is the network you use to connect with other PCs, printers, and devices in your work group. Your PC is probably already connected to the site LAN; you use the site LAN to connect to your intranet or to the Internet. If you want to share instruments with other users, or if you need access to instruments across an intranet or the Internet, you can use your site LAN. You may need to work with your IT department to put your instruments on the site LAN.

For more information on connecting a new instrument to your network (private or site LAN): 

LAN Direct Connection

GPIB Interfaces

A GPIB interface can be any of the following:

• Keysight 82350 PCI GPIB interface
• Keysight 82351 PCIe® GPIB Interface
• Keysight 82357 USB to GPIB converter

Connecting instruments via GPIB

The General Purpose Interface Bus (GPIB) is fast and robust, but requires a special PC card and additional configuration steps. Many existing systems are based on GPIB, and it is the best option for many instruments that have only GPIB and serial connectors.

USB Interfaces

Instruments connected via USB are auto-discovered. There are no editable parameters on a USB interface.

Important Notes

• Only USB instruments that implement the USBTMC protocol are shown. USB devices such as printers, scanners, and cameras do not implement the USBTMC protocol and do not appear in Instruments view. Instruments configured only for Easy File Access and not for USBTMC also do not appear.
  
  
• The 82357 USB-GPIB converter is not a USBTMC device. The 82357 appears as a USB/GPIB interface.

Connecting instruments via USB

The Universal Serial Bus (USB) is a quick and easy way to connect instruments to PCs. Some newer instruments have USB interfaces built in; for those that do not, you can use the Keysight 82357 USB/GPIB Interface to establish connectivity easily and inexpensively. You can use one USB port to connect a single instrument to a PC; or, via the 82357, you can connect up to 14 GPIB instruments to one USB port.