Lakeshore 336, User Manual

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6.4 Ethernet Interface 109
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When issuing queries or queries and commands together, the user program should:
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Properly format and transmit the query including the terminator as 1 string
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Prepare to receive a response immediately
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Receive the entire response from the instrument including the terminator
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Guarantee that no other communication is started during the response or for
50 ms after it completes
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Not initiate communication more than 20 times per second
Failure to follow these simple rules will result in inability to establish communication
with the instrument or intermittent failures in communication.
6.4 Ethernet
Interface
The Ethernet interface provides a means of connecting the Model 336 to an Ethernet
based computer network. Ethernet networks provide the ability to communicate
across large distances, often using existing equipment (the internet, pre-existing
local networks). The Ethernet interface of the Model 336 provides the ability to use
TCP socket connections (section 6.4.3) to send commands and queries to the instru-
ment using the common command set detailed in section 6.6. The Model 336 has an
embedded web interface that provides status information and
additional utilities (section 6.5).
Menu Navigation:
Interface
Q
Enabled
Q
Ethernet
6.4.1 Ethernet
Configuration There are several parameters for configuring the Model 336 Ethernet interface and
three methods for configuring these parameters. This section contains a brief expla-
nation of each of these. A comprehensive discussion of computer networking is
beyond the scope of this manual. These settings may depend on your network config-
uration; contact your network administrator for assistance.
6.4.1.1 Network Address Parameters
Network address parameters include the IP address, the subnet mask, and the gate-
way address. The network address parameters of the Model 336 can be configured
using one of three methods: DHCP, Auto-IP, or Static-IP. See section 6.4.1.2 for details
on each of these configuration methods.
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IP Address: an IP address is required for a device to communicate using TCP/IP,
which is the protocol generally used for Ethernet devices and the Model 336. The
IP version used by the Model 336 is IPv4. The IPv6 standard is not supported. All
references to the IP protocol from this point forward will be referring to IPv4.
An IP address is a 32-bit logical address used to differentiate devices on a net-
work. It is most often given in dotted decimal notation, such as nnn.nnn.nnn.nnn
where nnn is a decimal number from 0 to 255.
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Subnet Mask: a sub network, or subnet, is a group of devices within a network that
have a common, designated IP address routing prefix. A subnet mask is a 32-bit
“bit mask” that signifies which part of the IP address represents the subnet rout-
ing prefix, and which part represents the device’s address on the subnet. A subnet
mask is most often given in dotted decimal notation, such as nnn.nnn.nnn.nnn
where nnn is a decimal number from 0 to 255. When converted to a binary nota-
tion, the 32-bit subnet mask should consist of a contiguous group of ones, fol-
lowed by a contiguous group of zeros. The ones represent which bits in the IP
address refer to the subnet, and the zeros represent which bits refer to the device
address. For example, the default Static-IP Address of the Model 336 is
192.168.0.12, and the default Static Subnet Mask is 255.255.255.0. Converting
this subnet mask to binary shows that the first 24 bits are ones, and the last 8 bits