5 network cabling for profibus pa – Flowserve MX/QX Profibus DP/PA Field Unit User Manual
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PB DPV1 / PA Field Unit Installation and Maintenance FCD LMENIM2336-03 – 12/12
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2.2.5 Network Cabling for PROFIBUS PA
Network cabling should be in accordance with PROFIBUS Process Automation (PA) guidelines using
twisted-pair shielded cable. The data line is normally also used to supply power to the field devices.
PROFIBUS PA is a combination of the PROFIBUS-DP V1 protocol and the IEC 61158-2 transmission
technique.
The following items should be taken into account when planning the network:
• Transmission rate – Within a network, only one transmission rate can be used; typical restrictions
of PA are 31.25kbits/sec.
• The required number of nodes.
• The type of network components needed – Terminals, connectors, connecting cables, termination.
• The type of cable to be used and its characteristics.
• The number of segments and/or repeaters.
• The overall span of the network – Adding repeaters and long cable lengths can increase transmis-
sion time.
• Cable termination – Active termination resistors are required at the ends of all segments.
Tables 2.5 and 2.6 detail the recommended cable parameters and various types of cable that can be
used for network cabling. For additional guidelines, see the following publications:
• PROFIBUS Networks SIMATIC NET
6GK1970-5CA20-0AA1
• Technical Guideline – PROFIBUS PA User and Installation Guideline Version 2.2 February 2003,
PROFIBUS Guideline Order No. 2.092
Table 2.5 – Recommended PROFIBUS PA Cable Parameters (Type A – shielded twisted-pair)
Characteristic impedence
100 ohms ±20%
Maximum capacitance
2 nF/km
Loop resistance
44 ohms/km
Conductor cross-sectional area
0.8 mm
2
(AWG 18)
Maximum length of network (including spurs)
1900 m
Table 2.6 – Recommended PROFIBUS PA Cable Types
PA, Ex and Non-Ex
(ABB Automation Products GmbH)
NPC080-NO
PA, Ex and Non-Ex
(ABB Automation Products GmbH)
NPC150-NO
PROFIBUS FC Process Cable (Siemens AG)
6XV1 830-5.H10
PROFIBUS Data Cable (Beldon Wire & Cable)
3079A & 3076F
UNITRONICS Bus PA (Lapp Kabel GmbH)
2170 235 1x2x1.0