BNC 845-M - Manual (Page 4)

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Model 845-M Programmer’s Manual V1.1 2011
2. Programming the Model 845-M
The Model 845-M can be accessed though LAN, USB, or GIPB interface. All interfaces use standard SCPI
command set to pass commands to the device.
LAN
The Model 845-M signal generator can be remotely programmed via a 10/100/1000Base-T LAN interface and
LAN-connected computer using one of several LAN interface protocols. The LAN allows instruments to be
connected together and controlled by a LAN- based computer. LAN and its associated interface operations are
defined in the IEEE 802.2 standard.
The Model 845-M supports the following LAN interface protocols:
1) Socket based LAN: the application programming interface (API) provided with the instrument
supports general programming using the LAN interface under Windows operating system.
2) VXI-11
3) Telephone Network (TELNET): TELNET is used for interactive, one command at a time
instrument control.
4) Internet protocol optionally supported
For LAN operation, the signal generator must be connected to the LAN, and an IP address must be
assigned to the signal generator either manually or by using DHCP client service. Your system
administrator can tell you which method to use. (Most current LAN networks use DHCP.)
DHCP Configuration
If the DHCP server uses dynamic DNS to link the hostname with the assigned IP address, the hostname may be
used in place of the IP address. Otherwise, the hostname is not usable.
Ethernet Interface Connection and Setup
The Model 845-M fully supports the IEEE-802.3 standard. Most front panel functions (except power on/off)
can be remotely controlled via a network server and an Ethernet connection. The Model 845-M software
supports the TCP/IP network protocol.
Ethernet uses a bus or star topologies where all of the interfacing devices are connected to a central cable
called the bus, or are connected to a hub. Ethernet uses the CSMA/CD access method to handle simultaneous
transmissions over the bus. CSMA/CD stands for Carrier Sense Multiple Access/Collision Detection. This standard
enables network devices to detect simultaneous data channel usage, called a collision, and provides for a
contention protocol. When a network device detects a collision, the CSMA/CD standard dictates that the data
will be retransmitted after waiting a random amount of time. If a second collision is detected, the data is
again retransmitted after waiting twice as long. This is known as exponential back off.
The TCP/IP setup requires the following: