Siemens CP-8000 User Manual page 611

Periodical datapoint
A periodical datapoint is used for the exchange of a process signal or a derived information between the
I/O Master Module and the higher-level open-/closed-loop control function.
Periodical information
A periodical information has a deterministic transmission behavior and is used for the exchange of a pro-
cess signal or a derived information between the I/O Master Module and the higher-level open-/closed-
loop control function.
A periodical information is always transmitted in groups and consequently with the transmission already
have a chronologically consistent interrelationship.
Periodical transmission
Exchange of a process signal or a derived information between the I/O Master Module and the higher-
level open-/closed-loop control function.
PLC
ž Programmable Logic Controller
PRE
ž Protocol Element
Programmable logic controller
Digitally operating electronic system, designed for use in an industrial environment, which uses a pro-
grammable memory for the internal storage of user-oriented instructions for implementing specific func-
tions such as logic, sequencing, timing, counting and arithmetic, to control, through digital or analog inputs
and outputs, various types of machines or processes. Both the PC (PLC) and its associated peripherals
are designed so that they can be easily integrated into an industrial control system and easily used in all
their intended functions (acc. to IEC 61131-1, chapter 2.50).
Protocol element
Supplementary system element for communication with other automation units or control systems that
comunicates via the internal bus (ZBG-Bus) with the Master Module
PSR
SICAM TOOLBOX II configuration tool
PSTN
Public Switched Telephone Network
PT 100
Temperature-dependent resistance element with PT 100 characteristic
Q
R
RADIUS
Remote Authentication Dial-In User Service
Client-Server protocol that serves for the central administration of authentication, authorization and for the
accounting (AAA) for users which connect to a network. RADIUS is used with dial-up connections via mo-
dem, ISDN, VPN, WLAN (IEEE 802.1X) and DSL. The RADIUS Server provides for the service the au-
thentication (check of user name and password).
Routing
Routing of data streams: Messages are "routed" from their sources to their sinks. This works similar to di-
recting railroad cars by setting track switcher. Messages contain data point related information.
Retained variables
Variables in a non-volatile memory. The value of the variable is retained during a power failure.
Router
Network device for connecting two independent network segments as internet and LAN
RS-232
Standard for serial data transmission
RS-485
Standard for serial data transmission
RTS
Request to Send (switch on transmit device), control line of an RS-232 interface
SICAM A8000 / CP-8000 • CP-8021 • CP-8022 Manual
DC8-037-2.02, Edition 10.2017
Unrestricted
Glossary
611