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Glossary
Glossary-7
AutomationSystem S7-400 Hardwareand Installation
A5E00850741-01
HHardware Interrupt
Interrupt-triggering modules trigger a hardware interrupt in the case of a certain
event in the process. The hardware interrupt is signalled to theCPU. In accordance
with the priority of this interrupt, the corresponding organization block is then
executed.
IInstance Data Block
With the S7-400, each call of a function block in the STEP 7 user program is
assigned a data block which is generated automatically.In the instance data block,
the values of the input, output and in/out parameters as well as thelocal block data
are stored.
Interface, Multipoint
→Multipoint Interface.
Interrupt, Cyclic
→Cyclic Interrupt
Isolated
In the case of isolated I/O modules, the reference potentials of the control and load
circuits are galvanically isolated from each other,for example, by optocouplers,
relay contacts, or transformers. The I/O circuits can be connected to a common
potential.