Overview of LAN instruments
When ethernet ports became standard on computers, it was logical that instrumentation would follow.
The VXI-11 protocol, which was standardized on in the early 1990s, is the standard used to emulate
GPIB over ethernet.
Even though ethernet became the standard LAN technology on instruments, LAN instruments from
different vendors differed in the approach they took. Some vendors only supported static IP, whereas
others had DHCP, DLLA (Auto-IP), and static addressing. The LXI consortium was started to
standardize what should be in all instruments that conform to LXI.
An instrument that conforms to LXI version 1.3 must have the following:
• All three IP addressing modes: DHCP, Auto-IP, and static IP.
• A web server that has some standard ethernet configuration parameters:
â–ª IP configuration: IP address, subnet mask, gateway.
â–ª Password protection on anything that might change the instrument state.
â–ª A control on the web page that flashes an LED or some form of indicator on the front panel of
the instrument. LXI calls this the Device Identification Functionality. This allows you to identify
the web page you are currently looking at with the instrument. This helps you identify a
specific instrument in a rack of similar model instruments.
• A reserved URL in the instrument that provides an xml document that has standard configuration
information. This can be useful for software tools that need to identify the instruments and their
capabilities. The URL is http://<host>:<port>/lxi/identification.
• An IVI driver for the instrument.
• A LAN Status (fault) indicator.
• VXI-11 discovery protocol.
• LAN reset button or menu option. LXI calls this the LAN Configuration Initialize (LCI).
When the LXI-defined LAN reset is selected, the instrument reverts its LAN settings to a known
set of defaults. The default LAN settings for LXI instruments are:
â–ª DHCP and Auto-IP enabled. LXI refers to this as the Auto IP address mode (compared to the
manual address mode, which is fixed or static IP addressing).
â–ª Web password is reset to the factory default.
â–ª Ping responder enabled.
â–ª Dynamic DNS and mDNS enabled.
LXI Version 1.3 added the requirement of mDNS (multicast DNS) discovery.
To Next Page
Loading...
Need help?
General
