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NOTE
the computer and the signal generator shall generally not exceed 100 m (100Base-T and 10Base-T).
For more information about LAN communication, refer to: http://www.ieee.org
。
The knowledge of LAN
interface is introduced hereinafter.
1) IP address
When the signal generator is remotely controlled via LAN, the physical network connection shall
be guaranteed to be smooth. The address of the signal generator is set to the subnet where the main
control computer is located via menu “local IP”. For example: If the IP address of main control
computer is 192.168.12.0, the IP address of the signal generator shall be set to 192.168.12.XXX,
where XXX is a value between 1 and 255.
Only the IP address is required to establish a network connection. The VISA addressing string is
as follows:
TCPIP::host address[::LAN device name][::INSTR] or TCPIP::host address::port::SOCKET
Where,
TCPIP - network protocol used;
host address - IP address or host name of the instrument, for identification and control of the
controlled instrument;
The LAN device name defines the handle number of the protocol and sub-device (optional);
— The VXI-11 protocol is adopted for the 0# equipment;
— The newer high speed LAN instrument protocol is adopted for the 0# high speed LAN
instrument;
The INSTR represents the instrument resource type (optional);
The port represents the socket port number;
SOCKET is resource class of original network socket.
Method for identification of multiple instruments in the remote control system
If multiple instruments are connected to the network, they can be identified by their individual IP
address and associated resource string. The main control computer uses the respective VISA
resource string for instrument identification.
2) VXI-11 protocol
The VXI-11 standard is based on the ONC RPC (Open Network Computing Remote Procedure
Call) protocol, which is the network/transport layer of the TCP/IP protocol. TCP/IP network protocol
and related network services are pre-configured. In communication, such connection-oriented
communication follows sequential exchange and can identify the interruption of connection to ensure
no information is lost.
3) Socket communication
TCP/IP protocol connects signal generator in the network through LAN socket. As a basic
computer network programming method, the socket enables applications with different hardware and
operating systems to communicate in the network, This method enables two-way communication
between the signal generator and the computer via port.
The socket is a special software class that defines the necessary information for network
communication such as IP address and device port number and integrates some basic network
programming operations. Sockets can be used in the operating system installed with a packaged
library. UNIX Berkeley socket and Winsock are commonly used.
The socket in the signal generator is compatible with Berkeley socket and Winsock through
Application Program Interface (API). In addition, other standard sockets are also compatible through
the API. When the signal generator is controlled using SCPI, the socket program created in the
