Vega VEGABAR 51 Operating Instructions Manual page 49

Checking Profibus PA
VEGABAR 51 • Profibus PA
The hotline is available to you 7 days a week round-the-clock. Since
we offer this service world-wide, the support is only available in the
English language. The service is free of charge, only the standard
telephone costs will be charged.
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When an additional instrument is connected, the segment fails.
Max. supply current of the segment coupler exceeded
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à Measure the current consumption, reduce size of segment
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Wrong presentation of the measured value in Simatic S5
Simatic S5 cannot interpret the number format IEEE of the
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measured value
à Insert converting component from Siemens
? In Simatic S7 the measured value is always presented as 0
Only four bytes are consistently loaded in the PLC
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à Use function component SFC 14 to load 5 bytes consistently
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Measured value on the indicating and adjustment module does not
correspond to the value in the PLC
The menu item "Display - Display value" is not set to "PA-Out"
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à Check values and correct, if necessary
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No connection between PLC and PA network
Incorrect adjustment of the bus parameter and the segment
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coupler-dependent baud rate
à Check data and correct, if necessary
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Instrument does not appear during connection setup
Profibus DP cable pole-reversed
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à Check cable and correct, if necessary
Incorrect termination
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à Check termination at the beginning and end points of the bus
and terminate, if necessary, according to the specification
Instrument not connected to the segment, double assignment
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of an address
à Check and correct, if necessary
In Ex applications, the regulations for the wiring of intrinsically safe
circuits must be observed.
8 Maintenance and fault rectification
49