Technical data

144 Agilent Connectivity Guide
6 Programming Your Instruments
LAN Networking Protocols
There are two LAN networking protocols provided with the Agilent IO
Libraries Suite software. You can use one or both of these protocols
when configuring your systems to use VISA and SICL over LAN.
SICL-LAN Protocol is a networking protocol developed by
Agilent that is compatible with all VISA LAN products. This
LAN networking protocol is the default choice in the Agilent IO
Libraries Suite configuration when configuring the LAN
interface. The SICL-LAN protocol on Windows supports VISA
operations over LAN to GPIB interfaces.
VXI-11 (TCP/IP Instrument Protocol) is a networking protocol
developed by the VXIbus Consortium based on the SICL-LAN
Protocol that permits interoperability of LAN software from
different vendors who meet the VXIbus Consortium standards.
When using either of these networking protocols, the LAN software
uses the TCP/IP protocol suite to pass messages between the LAN
device and the server. The server accepts device I/O requests over the
network from the device and then proceeds to execute them.
By default, the LAN supports both protocols by automatically detecting
the protocol the server is using. When a VISA viOpen or SICL iopen
call is performed, the LAN interface driver first tries to connect using
the SICL-LAN protocol. If that fails, the driver will try to connect using
the VXI-11 protocol.
If you want to control the protocol used, you can configure more than
one LAN interface using Connection Expert and set each interface to a
different protocol. The protocol used will then depend on the interface
you are connecting through.
In VISA, the protocol used is determined by the configuration settings
and cannot be changed programmatically. In SICL, you can override the
configuration settings programmatically by specifying the protocol in
the iopen string.
Example: Using Network Protocols in SICL
Some examples using VXI-11 and SICL-LAN protocol follow. Note
that SICL names are case-sensitive.