Siemens SIMATIC ET 200M Operating Instructions Manual page 264

Glossary
PROFINET IO Controller
Device used to address connected IO devices. That means: the IO controller exchanges
input and output signals with assigned field devices. The IO controller is usually the
controller running the automation program.
PROFINET IO Device
Distributed field device which is assigned to one of the IO controllers (remote IO, valve
blocks, frequency converters, switches.)
Programmable logic controller
Programmable logic controllers are electronic control systems that are stored as programs in
the control device. Thus, neither setup nor wiring of the device depend on the control
system's function. The programmable logic controller is structured like a computer: it consists
of a CPU with memory, I/O modules and an internal bus system. IO devices and
programming language are aimed at control technique requirements.
Programming device
Programming devices are essentially compact and mobile PCs that are suitable for industrial
purposes. They are equipped with special hardware and software for programmable logic
controllers (SIMATIC).
Punch value
Punch values are values issued to the process due to faulty signal output modules.
Alternatively they are used for faulty signal input modules in the user program instead of
process values. Punch values can be pre-configured by the user (e.g. maintaining the old
value).
Redundant systems
Redundant systems are characterized by multiple (redundant) occurrences of important
automation components. Failure of a redundant component will not cause program
processing to be interrupted.
Reference potential
Potential that is used to view and/or measure voltages for each circuit involved.
Response monitoring
is a slave parameter. If a DP Slave is not addressed during the response monitoring time, it
will switch to safe mode and set its outputs to "0".
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Operating Instructions, 12/2008, EWA-4NEB780600602-08
ET 200M