Siemens S7-400 Functional Grounding, Function Block FB, Function Module FM, Ground verb, GSD File

Glossary

Functional Grounding

Grounding whose only purpose is to ensure the intended function of the electrical equipment concerned. Functional grounding short-circuits any noise that might otherwise have a detrimental effect on the equipment.

Function Block (FB)

According to IEC 61131-3, a function block (FB) is a code block that contains static data. It is assigned an instance DB as memory. All parameters and static tags passed to the FB are stored in the instance DB. Its temporary data are stored in the local data stack.

Data in the instance DB are retentiveAn FB allows parameters to be passed in the user program. Function blocks are therefore suitable for programming complex functions, e.g. closed-loop controls, mode selections, which are repeated frequently

Function Module (FM)

A programmable module which, in contrast to the CPU, has no multipoint interface and can only be operated as a slave.

G

Global Data Communication

Global data communication is a procedure with which shared data are transferred between CPUs.

Ground

The conductive mass of the ground whose potential can be assumed to be zero at any point.

In the vicinity of ground electrodes, the ground may have a potential other than zero. The term “reference ground” is often used in this situation.

Ground (verb)

To ground means connecting an electrically conductive part via a grounding system to ground (one or more electrically conductive parts that have good contact with the soil).

GSD File

The device master file (GSD file) contains all slave-specific data. The format of GSD files is specified in EN 50170, Volume 2, PROFIBUS.

Glossary-6	Automation System S7-400	Hardware and Installation
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