User`s guide

124 Agilent VISA User’s Guide
5 Programming via LAN
viClose(defaultRM);
Using a Remote Interface for LAN Access
Agilent VISA provides three types of VISA LAN Client interfaces,
implemented in Agilent IO Libraries Suite as remote interfaces:
• Remote serial interface (ASRL VISA LAN Client)
• Remote GPIB interface (GPIB VISA LAN Client)
• Remote USB interface (USB VISA LAN Client)
Remote interfaces are configured using Connection Expert; they
provide virtual GPIB, serial, or USB interfaces. They make it possible
to remotely access a LAN-connected device as if it were connected to a
local interface. If, for example, the GPIB2 interface is configured as a
remote GPIB interface, a program controlling the devices
GPIB2::5::INSTR and GPIB2::7::INSTR would not be aware of the
fact that these devices are actually connected via LAN and not to a
GPIB interface connected to the local machine.
See the Agilent IO Libraries Suite Online Help for specific information
on configuring remote interfaces.
Remote Serial Interface (ASRL VISA LAN Client)
A remote serial interface can use only the SICL-LAN protocol. A
remote serial interface can be configured to use the serial port on the
Agilent E5810 LAN/GPIB gateway or the serial ports on a PC running
the Remote IO Server software.
Remote GPIB Interface (GPIB VISA LAN Client)
A remote GPIB interface can use both the VXI-11 and SICL-LAN
protocols. Typical uses for remote GPIB interfaces are with LAN/GPIB
gateways (e.g. Agilent E5810), PCs with GPIB interfaces that are
running a LAN server, and VXI-11.2 LAN-based instruments.
A remote GPIB interface can only be used to communicate with
VXI-11.2 (GPIB Emulation) devices. This is because the VISA GPIB
interface type requires a primary and (optionally) a secondary address
when communicating with a device. VXI-11.3 devices do not support
the concept of a primary address, so they cannot be accessed with a
remote GPIB interface.