Siemens 2000592-001 User Manual page 67

Definitions
Overview
Advance Network
Gateway Ethernet
Ethernet
Collisions
CRC - Cyclic
Redundancy Check
DataNET
Data Hiway
2000592-001
Glossary
This section defines important Terms.
The Advance Network Gateway Ethernet (ANG_EN) is a wall- (or rack-)
mounted unit that is self-contained with power supply and all electronics.
It provides internal field termination points to connect standard Advance
Data Hiway cable "on one side" and Ethernet 10BaseT cabling
(Unshielded Twisted Pair) "on the other side". The Gateway unit requires
120 VAC power wired directly to it.
A data link level protocol comprising the OSI model's bottom two layers.
It is a broadcast networking technology that can use several different
physical media, including twisted-pair cable and coaxial cable. Ethernet
usually used CSMA/CD. TCP/IP is commonly used with Ethernet
networks.
The result of two or more LAN stations attempting to use the same
transmission medium at the same time. Collisions are a normal
occurrence on Ethernet. A properly functioning Ethernet will experience a
relative small percentage of collisions. Typically the collision rate should
be less than 5% of the available bandwidth. Most collisions occur during
the preamble portion of the frame. Most Ethernet controllers
automatically retry, up to 15 times, any packet that has a collision during
transmission. (Except for Late Collisions)
CRC is a method to detect errors. A number is derived from the data that
will be transmitted. By recalculating the CRC at the remote end and
comparing it to the value originally transmitted, the receiving node can
detect errors.
The name "DataNET" is used to mean the high-speed communication
system inclusive of our application software.
The term "Data Hiway" refers to the Advance Optichrom Network. The
Advance Network Gateway and DataNET Gateway are used to bridge
the Advance Optichrom network and the Advance DataNET network.
Glossary • 57