Installation – Lenze EMF2133IB User Manual
Page 25
Installation
Electrical installation
Wiring with a host (master)
l
25
EDSMF2133IB EN 5.0
Number of bus devices
M
1
2
3
S
S
S
S
S
R
R
2133PFB004
Segment
Master (M)
Slave (S)
Repeater (R)
1
1
2
31
30
−
−
2
−
30
1
3
−
30
1
I
Tip!
Repeaters do not have a device address. When calculating the maximum
number of bus devices, they reduce the number of devices by 1 on each side of
the segment.
Repeaters can be used to build up line and tree topologies. The maximum total
bus system expansion depends on ...
ƒ
the baud rate used;
ƒ
the number of repeaters used.
Specification of the transmission cable
)
Note!
Only use cables complying with the listed specifications of the PROFIBUS user
organisation.
Field
Values
Specific 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
Twisted double, insulated and shielded