Lenze EPM−T9XX Modular system - Manual (Page 166)

PROFIBUS−DP
Wiring
7
Electrical installation
7.5
7.5.1
L
7.5−2 EDSPM−TXXX−9.0−11/2009
M
1 2 3
S S S S S
R R
2133PFB004
Fig. 7.5−2 Number of nodes in the bus system PROFIBUS−DP
Segment Master (M) Slave (S) Repeater (R)
1 1
2 31
30 −
−
2 − 31 1
3 − 30 2
)
Note!
Repeaters do not have a device address, but they are also
included in the calculation of the maximum slave number of
nodes.
Repeaters can be used to create line and tree topologies. The
maximum total extension of the bus system depends on
l the used baud rate,
l the number of repeaters.
Baud rate [kBit/s] Length [m]
9.6 − 93.75 1200
187.5 1000
500 400
1500 200
3000 − 12000 100
Please follow our recommendations for signal cables.
Specification bus cable
Cable resistance 135 − 165 W/km, (f = 3 − 20 MHz)
Capacitance per unit length £ 30 nF/km
Loop resistance < 110 W/km
Core diameter > 0.64 mm
Core cross−section > 0.34 mm 2
Cores Double twisted, insulated and shielded
Number of bus stations
Baud rate / length of bus cable
Specification of the transmission
cable
6