Profibus Cables And Connectors - Siemens SINUMERIK 840D sl Manual

Connecting
7.8 PROFIBUS DP
7.8.2

PROFIBUS cables and connectors

Cable specification
The PROFIBUS cable is 2-wire, twisted, and shielded with defined technical data.
Table 7-20
Characteristics
Connector type
Cable type
Max. cable length
Table 7-21
Characteristics
Wave impedance
Loop resistance
Effective capacitance
Damping
Permissible conductor cross section
Permissible cable diameter
Cable lengths and data rate
The data rate determines the cable length of a subnet segment.
Table 7-22
Data rate
19.6 to 187.5 kbit/s
500 kbit/s
1.5 Mbit/s
3 to 12 Mbit/s
1)
Longer cable lengths:
If you must realize greater cable lengths than permitted in one segment, you must use RS 485
repeaters. The maximum possible cable lengths between two RS 485 repeaters correspond
to the cable length of a segment. You can connect up to 9 RS 485 repeaters in series.
Note that an RS 485 repeater must be counted as a subnet node when determining the total
number of nodes to be connected. This is true even if the RS 485 repeater is not assigned its
own PROFIBUS address.
66
Cable specifications for X126 and X136
Technical data for PROFIBUS cables
Permitted cable length of a subnet segment for specific data rates
With isolated interface
Version
9-pin SUB D connector
PROFIBUS cable
100 m at 12 Mbit/s
Values
Approximately 135 to 160 Ω (f = 3 to 20 MHz)
≤ 115 Ω/km
30 nF/km
0.9 dB/100 m (f = 200 kHz)
0.3 mm to 0.5 mm
2 2
8 mm + 0.5 mm
Max. cable length of a segment (in m)
1000
1)
400
200
100
Manual, 06/2014, 6FC5397-1EP40-5BA1
NCU 7x0.3 PN, NCU 7x0.3B PN