Glossary
SINAUT ST7 Station control system - System Manual
System Manual, 05/2007, C79000-G8976-C178-06
317
application. Ethernet is designed with a linear or star topology. The transmission media are
shielded coaxial cables, twisted pair, or fiber-optic cables. SIMATIC NET Industrial Ethernet
uses both the Ethernet and Fast Ethernet standards.
Ethernet TIM
A TIM module of the type TIM 3V-IE, TIM 3V-IE Advanced or TIM 4R-IE.
Firewall
A firewall is a network component via which a secure network can be linked with an
unsecure network. The task of a firewall is to control data exchange between the networks.
General request (GR)
With a general request, the master station can update itself. All messages and the current
content are requested from the stations. This allows the master station to obtain an up-to-
date process image.
GPRS
(General Packet Radio Service)
GPRS is an expansion of GSM mobile wireless that adds packet-oriented data transmission.
Network connections are established over GPRS either in the Internet or in private networks.
The data is transmitted using the Internet protocols TCP/IP or UDP/IP.
GPS
(Global Positioning System)
GPS is a worldwide US satellite navigation system for highly accurate location, navigation
and time distribution. It operates with 24 orbiting satellites (21 operational and 3 spare
satellites) on six satellite orbits at a height of approximately 20,000 kilometers. Each satellite
contains an atomic clock whose time is transmitted continuously along with the orbit data.
The GPS receiver receives data from a maximum of six satellites and calculates its position
based on these values. Once the position has been calculated, the transmission time of the
data from the individual satellites can be calculated. The GPS world time (UTC) is calculated
in the system based on these values.
GSM
(Global System for Mobile communications)
Worldwide standard for wireless transmission of voice, data, fax and text messages (SMS).
There are GSM-based wireless networks found in many countries in particular in Europe,
China, Latin America as well as in many regions of the USA, Russia and Africa. A distinction
is made according to frequencies: PCS 850 MHz, GSM 900 MHz, DCS 1800 MHz and PCS
1900 MHz.
