Proline Promass 83 PROFIBUS DP/PA Wiring
Endress+Hauser 27
Spurs
Note the following points:
• Length of spurs < 6.6 m (at max.1.5 MBit/s)
• No spurs should be used for transmission rates >1.5 MBit/s. The line between the connector and
the bus driver is described as a spur. Experience has shown that you should proceed with caution
when configuring spurs. For this reason, you cannot presume that the sum of all spurs at
1.5 MBit/s may be 6.6 m. This is affected greatly by the arrangement of the field devices.
Therefore, we recommend you do not use any spurs, if possible, at transmission rates
>1.5 MBit/s.
• If you cannot avoid using spurs, then they may not include any bus terminators.
Further information
General information and further notes regarding the wiring can be found in BA038S/04: “Field
communication PROFIBUS DP/PA: Guidelines for planning and commissioning”.
4.1.2 PROFIBUS PA cable specifications
Cable type
Twin-core cables are recommended for connecting the device to the fieldbus. Following
IEC 61158-2 (MBP), four different cable types (A, B, C, D) can be used with the fieldbus, only two
of which (cable types A and B) are shielded.
• Cable types A or B are particularly preferable for new installations. Only these types have cable
shielding that guarantees adequate protection from electromagnetic interference and thus the
most reliable data transfer. In the case of type B multi-pair cables, it is permissible to operate
multiple fieldbuses with the same degree of protection on one cable. No other circuits are
permissible in the same cable.
• Practical experience has shown that cable types C and D should not be used due to the lack of
shielding, since the freedom from interference generally does not meet the requirements
described in the standard.
The electrical data of the fieldbus cable have not been specified but determine important
characteristics of the design of the fieldbus, such as distances bridged, number of users,
electromagnetic compatibility, etc.
Suitable fieldbus cables from various manufacturers for non-hazardous areas are listed below:
• Siemens: 6XV1 830-5BH10
• Belden: 3076F
• Kerpen: CeL-PE/OSCR/PVC/FRLA FB-02YS(ST)YFL
Type A Type B
Cable structure Twisted pair,
shielded
One or more twisted pairs, fully shielded
Wire cross-section 0.8 mm
2
(AWG 18) 0.32 mm
2
(AWG 22)
Loop-resistance (DC) 44 Ω/km 112 Ω/km
Characteristic impedance at 31.25 kHz 100 Ω ± 20% 100 Ω ± 30%
Attenuation constant at 39 kHz 3 dB/km 5 dB/km
Capacitive asymmetry 2 nF/km 2 nF/km
Envelope delay distortion (7.9...39 kHz) 1.7 µs/km *
Shield coverage 90% *
Max. cable length (incl. spurs >1 m) 1900 m 1200 m
* Not specified
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