Technical data

Glossary • 349
WAGO-I/O-SYSTEM 750
BACnet/IP Controller
RS232
The RS232 (official designation ANSI/EIA/TIA-232-F-1997) is a serial in-
terface for point-to-point connections. "RS" stands for "Radio Sector", but is
frequently translated as "Recommended Standard".
Data is transmitted via this interface bit-serial over a data line and received
on a different data line. As only one data line is used at a time, the data is
transmitted time-delayed consecutively and asynchronously. The time inter-
vals between transmission of the data may be randomly long.
As the RS232 interface is a so-called powered interface, data is transferred
electrically encoded.
The cable connections used for this interface are 9-pin Sub-D connectors
and 9-pin jacks. A distinction is made here between data lines (RxD, TxD
and GND) and control lines (DCD, DTR, DSR, RTS, CTS and RI).
S
SCADA (Supervisory Control and Data Acquisition)
SCADA software is a program for the control and visualization of processes
(supervisory control and data acquisition).
Segment
Typically, a network is divided up into different physical network segments
by way of routers or repeaters.
Server
Service-supplying device within a Client Server System. The service is re-
quested by the Client.
Service
A service is an operation (Read, Write) oriented toward an object.
BACnet specified standardized services that are transmitted via a special
BACnet network layer. Communication is based on the client/server
method: The client makes requests to the server. The server processes the
requests from the client and then transmits a response. A distinction is made
between 38 services that are broken down into 5 categories: Alarm and
events, object access, file access, remote device access, virtual terminal ser-
vices