Siemens SIMATIC NET PROFIBUS manual GAP factor, Ground

Glossary

Electromagnetic compatibility (EMC)

Electromagnetic compatibility (EMC) deals with all questions of electrical, ma- gnetic and electromagnetic emission and immunity and the functional disturban- ces in electrical devices resulting from these effects.

Fiber-optic cable (FO)

A fiber-optic cable is a transmission medium in an optical network.

FISCO

A model (FISCO – Fieldbus Intrinsically Safe COncept) created by the PTB in cooperation with well–known manufacturers describing one method of implemen- ting an “i” fieldbus for use in hazardous areas. This model is characterized by there being only one “active” device, the bus power supply, connected to the fieldbus. The other devices are all “passive” in terms of their ability to supply power to the cable. The characteristics of the cables do not influence the intrinsic safety (within certain limits).

GAP factor

GAP update factor. The gap between the local PROFIBUS address of the ma- ster to the next PROFIBUS address of a master is known as the GAP. The GAP update factor specifies how many token rotations the master waits before chek- king whether there is another master in the GAP.

For example, if the GAP update factor is 3, this means that each master checks whether a new master is located between its own PROFIBUS address and the PROFIBUS address of the next master after approximately 3 token rotations.

Ground

Ground is the conductive ground area whose potential at any point can be taken as zero.

Grounding

Grounding means connecting a conductive part to ground via a grounding sy- stem.

GSD

Device data bases (GSD files) contain DP slave descriptions in a uniform format. The use of GSD files makes it easier to configure the master DP slave.

IP 20

Degree of protection complying with DIN 40050: Protection against touch with fingers and against the penetration of solid foreign bodies with more than 12 mm

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Glossary-2	PROFIBUS Networks SIMATIC NET
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