Siemens SIMATIC ET 200S Manual page 201

PROFIBUS
Process Field Bus is a German process and field bus standard, defined in
IEC 61784-1:2002 Ed1 CP 3/1. It specifies functional, electrical and mechanical
characteristics of a bit serial field bus system.
PROFIBUS is available with the protocols DP (the German abbreviation for
distributed I/O), FMS (= field bus message specification), PA (= process
automation) or TF (= technology (process-related) functions).
PROFIBUS Address
Each bus node must receive a PROFIBUS address to identify it uniquely on the
PROFIBUS bus system.
The PC/PD has the PROFIBUS address "0".
The PROFIBUS addresses 1 to 125 are permissible for the ET 200S distributed
I/O system.
Programmable logic controller
A programmable logic controller (PLC) is an electronic controller whose function
is stored in the control unit as a program. The configuration and wiring of the
device therefore is not determined by the function of the controller. The
programmable logic controller is structured like a computer; it consists of a ³
CPU (central module) with a memory, input/output modules and an internal bus
system. The I/O and the programming language are designed to meet the
requirements of the control technology.
Programming device
Programming devices are basically personal computers that are suitable for the
industrial environment, compact and transportable. They are equipped with
special hardware and software for SIMATIC programmable controllers.
Publisher
A sender in direct data communication See Direct Communication
Restart
When a CPU is started up (e.g. by switching the mode selector from STOP to
RUN or by switching the power on), the organization block OB 100 (complete
restart) is executed before cyclic program scanning (OB 1) commences. In the
event of a restart, the process image of the inputs is read in and the STEP 7
user program is processed beginning with the first command in OB 1.
ET 200S IM 151-7 CPU Interface Module
A5E00058783-04
Glossary
Glossary-9