Guidelines for Bus Segment Installation
The following guidelines apply for wiring bus segments:
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Type "A" bus cable which complies with PROFIBUS standards is to be used the bus.
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The bus cable may not be twisted, pinched or stretched.
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A bus segment must be fitted with a termination resistor on both ends.
The corresponding slave must be live at all times so that the termination resistor is effective however.
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Bus nodes that do not terminate a segment can be separated from the bus without interrupting regular data traffic.
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Branch lines are not allowed.
In Cabinets
Cable locations play a major role in the resistance to interference. Therefore, the following guidelines are applied:
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Data lines must be separated from all AC and DC power lines >= 60 V.
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A minimum spacing of 20 cm is to be kept between data lines and power lines.
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AC and DC feed wires > 60 V and <= 230 V must be run separately from AC and DC power feeds > 230 V
Separated means that the cables are in different cable bundles and ducts.
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PG screws with integrated grounding are not allowed.
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Cabinet lighting must be done with EMC safe lights and wiring.
Outside of Cabinets
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Cables must be run in metal cable ducting (lines, troughs, ducts or tubing) wherever possible.
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Only wires of < 60 V or shielded < 230 V may be run in common cable ducts.
Dividers in metal cable ducts may be used as long as the minimum spacing of 20 cm is kept between wires.
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PROFIBUS data lines must be run separately in metal cable ducts.
Wiring outside of buildings
Generally, the same rules apply for running lines outside of buildings as within.
However, the following applies to bus cable:
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Run in a suitable plastic tubing.
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When burying cables, only cable that is specifically designed for this purpose may be used.
Pay special attention to the permitted temperatures.
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When running cables between buildings, use .
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For baud rates over 500 kBaud, fiber optics cable is recommended.
