Tension Electronics PFEA111/112, User Manual
Chapter 3 Commissioning
3-26 3BSE029380R0101 Rev C
3.13.3 Profibus Physical Media
The bus line is specified in EN 50170 as line type A. Line type B should be avoided.
The physical properties of the media are shown in Table 3-5 and Table 3-6.
The specified line parameters result in the following lengths of a bus segment.
Stub lines up to 1500 kbit/s < 6.6 m.
If you are using 12 Mbits/s you should avoid stub lines.
If you are using line A as specified by EN 50 170, the bus terminating resistance combination
is as shown in Figure 3-18, so that a defined idle state potential is ensured on the line.
Table 3-5. Line Parameters
Parameter Line type A
Line type B
(Avoid if possible)
Impedance in 135 to 165 100 to 130
Capacitance per unit length (pF/m) <30 <60
Loop resistance ( /km) 110 ---
Core diameter (mm) 0.64 > 0.53
Core cross section (mm
2
) > 0.34 > 0.22
Table 3-6. Maximum Cable Lengths per Segment
Maximum bus
segment length (m)
Transmission rate in kbit/s
9.6 19.2 93.75 187.5 500 1500 12000
Wire A 1200 1200 1200 1000 400 200 100
Wire B 1200 1200 1200 600 200 - -
Figure 3-18. Line Termination of Wire A in Accordance with EN 50170
Signals on the Connector
Pin No. in Brackets
VP(6)
Data line - B(3)
Data line - A(8)
GND (5)
Terminating Resistance of the Bus
390
390
220
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