Siemens Automation System S7-400 - Manual (Page 215)

Glossary
Glossary-7
Automation System S7-400 Hardware and Installation
A5E00850741-01
H
Hardware Interrupt
Interrupt-triggering modules trigger a hardware interrupt in the case of a certain
event in the process. The hardware interrupt is signalled to the CPU. In accordance
with the priority of this interrupt, the corresponding organization block is then
executed.
I
Instance 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 the local 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.