Lake Shore 350, User Manual

Page: 140 / 192

126 c
HAPTER
6: Computer Interface Operation
Model 350 Temperature Controller
D
Module Error: the Model 350 has lost contact with the Ethernet module; this may
indicate a damaged Ethernet module
D
Acquiring Address: the Model 350 is attempting to configure the IP address
parameters using the enabled methods
6.4.2.2 MAC Address
The Media Access Controller (MAC) Address is a physical hardware address assigned
to all Ethernet devices. MAC addresses are 48-bits and are generally written as six
groups of two hexidecimal digits separated by colons, for example
“01:23:45:67:89:AB”. Unlike IP addresses, MAC addresses are tied to the device hard-
ware and cannot be changed.
Menu Navigation (Read-Only):
Interface
Q
View IP Config
Q
MAC Address
6.4.2.3 Viewing Network Configuration Parameters and DNS Parameters
The currently configured network parameters are displayed individually in the View
IP Config submenu. These parameters could have been configured using either DHCP,
Auto-IP, or Static-IP. The LAN Status parameter shows which method was used for the
current configuration. When in an error state, or in the intermediate Acquiring
Address state, the network configuration parameters will all be displayed as 0.0.0.0.
Refer to section 6.4.1.1 through section 6.4.1.3 for details on network configuration
parameters and DNS parameters.
Menu Navigation (Read-Only):
Interface
Q
View IP Config
Q
IP
Interface
Q
View IP Config
Q
Subnet Mask
Interface
Q
View IP Config
Q
Gateway IP
Interface
Q
View IP Config
Q
Primary DNS IP
Interface
Q
View IP Config
Q
Secondary DNS IP
Interface
Q
View IP Config
Q
Actual Hostname
Interface
Q
View IP Config
Q
TCP Socket Port
6.4.3 TCP Socket
Communication A TCP socket connection interface is provided as the communication medium for the
Ethernet interface of the Model 350. A TCP socket connection, or simply “socket con-
nection”, is a common connection protocol used by Ethernet devices. The Transmis-
sion Control Protocol (TCP) is commonly used for creating a communication channel
between one program on one computer and one program on another computer, for
example a web browser on a PC and a web server on the Internet. In the case of the
Model 350, the protocol is used to create a communication channel between one
program on one computer and the command line interface of the Model 350. TCP
uses error correction and collision avoidance schemes that make it a very reliable
form of Ethernet communication, but has drawbacks of having nondeterministic tim-
ing, and can encounter relatively large delays depending on network conditions.
These delays can be on the order of seconds. Sockets use port numbers to identify
sending and receiving endpoints on network devices. This allows for multiple sepa-
rate communication links to exist on each device.
The port number used for TCP socket
connections on the Model 350 is 7777.
A maximum of two simultaneous socket connections can be made to the Model 350. Any
attempts to open a new socket while two socket connections are already open on a
Model 350 will fail.