II - DCE FEL ČVUT v Praze

Glossary
Hardware interrupt
Process image
Programmable
logic controller
PROFIBUS
PROFIBUS-DP
PTB
Glossary-10
A hardware interrupt is tripped by interrupt-capable S7-300 modules as a
result of a specific event occurring during the process. This interrupt is
reported to the CPU. The assigned organization block is then processed
according to the interrupt priority.
In SIMATIC S7/M7: An operating range is defined by parameterizing an
upper limit value and a lower limit value, for example. If the process signal
(e.g. temperature) of an analog input module leaves this range, the module
outputs a hardware interrupt, providing hardware interrupts have been
enabled for it. The CPU stops processing the user program and any events
with lower priority classes and processes the hardware interrupt block instead
(OB 40).
In SIMATIC S5: The hardware interrupt is simulated as part of the
device-specific diagnostics. You can detect hardware interrupts (e.g. an
overrange condition) by cyclically interrogating the diagnostic bits of this
diagnostics.
A special memory area in the automation system. The signal states of the
input modules are copied to the process image of the inputs at the start of the
cyclic program. At the end of the cyclic program, the process image of the
outputs is copied to the output modules as the signal state.
A programmable logic controller (PLC) is an electronic control circuit whose
automation function is stored as a software program. Accordingly, the
configuration and wiring of the PLC are not dependent on the automation
assignment.
The PLC is constructed as a computer; it consists of a CPU module with
memory, I/O modules and an internal bus system. The I/O modules and
the programming language are tailored to the needs of automation programs.
PROcess FIeld BUS, the German standard for this type of bus, which is
defined in EN 50170. It lays down the functional, electrical and mechanical
characteristics of a bit-serial field bus system.
PROFIBUS is a bus system which enables PROFIBUS-compatible
automation systems and I/O units at the cell and field levels to be networked
together. It operates with the following protocols: DP (= distributed I/O),
FMS (= field bus message specification) and TF (= process function).
PROFIBUS bus system with the DP protocol. DP is the German abbreviation
for distributed I/O. The ET 200 distributed I/O system is based on
EN 50 170, Volume 2, PROFIBUS.
Physikalisch-Technische Bundesanstalt. Product certification center in
Germany.
I/O Modules with Intrinsically-Safe Signals
C79000-G7076-C152-04