Profibus Cables And Connectors - Siemens SINUMERIK ONE NCU 1740 Equipment Manual

8.9.2

PROFIBUS cables and connectors

Cable specification
The PROFIBUS cable is 2-wire, twisted, and shielded with defined technical data.
Table 8-14
Characteristics
Connector type
Cable type
Max. cable length
Table 8-15
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 8-16
Data rate
19.6 to 187.5 kbit/s
500 kbit/s
1.5 Mbit/s
3 to 12 Mbit/s
With isolated interface
1)
Longer cable lengths:
If you must realize longer 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.
NCU 1740
Equipment Manual, 10/2021, A5E51087503B AA
Cable specification for X126
Technical data for PROFIBUS cables
Permitted cable length of a subnet segment for specific data rates
Version
9-pin SUB-D socket
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 2 to 0.5 mm 2
8 mm + 0.5 mm
Max. cable length of a segment (in m)
1000
1)
400
200
100
Connecting
8.9 PROFIBUS DP
75