Glossary
S7-300, CPU 31xC and CPU 31x: Installation
Glossary-8
Operating Instructions, Edition 08/2004, A5E00105492-05
Hub
See Switch
In contrast to a switch, a hub sets itself to the lowest speed at the ports and forwards the
signals to all connected devices. A hub is also not capable of giving priority to signals. This
would lead to a high communication load on Industrial Ethernet.
Industrial Ethernet
See Fast Ethernet
Industrial Ethernet (formerly SINEC H1) is a technology that allows data to be transmitted
free of interference in an industrial environment.
Due to the openness of PROFINET, you can use standard Ethernet components. We
recommend, however, that you install PROFINET as Industrial Ethernet.
Instance data block
The STEP 7 user program assigns an automatically generated DB to every call of a function
block. The instance data block stores the values of inputs / outputs and in/out parameters, as
well as local block data.
Interface, MPI-capable
See MPI
Interrupt
The CPU operating system knows 10 different priority classes for controlling user program
execution. These priority classes include interrupts, e.g. process interrupts. When an
interrupt is triggered, the operating system automatically calls an assigned OB. In this OB
the user can program the desired response (e.g. in an FB).
Interrupt, cyclic interrupt
A cyclic interrupt is generated periodically by the CPU in a configurable time pattern. A
corresponding OB will be processed.
Interrupt, delay
The delay interrupt belongs to one of the priority classes in SIMATIC S7 program
processing. It is generated on expiration of a time started in the user program. A
corresponding OB will be processed.
Interrupt, delay
See Interrupt, delay
Interrupt, diagnostic
See Diagnostic Interrupt