Profibus Cable - Siemens SIMOTION P320-4 E Commissioning And Hardware Installation Manual

Connecting the bus connector
Proceed as follows to connect the bus connector:
1. Plug the bus connector into the IsoPROFIBUS interface on the module.
2. Screw the bus connector onto the interface.
3. If the bus connector is located at the start or end of a segment, you must connect the
terminating resistor (switch position "ON").
Figure 5-9
5.5.6

PROFIBUS cable

Properties of the PROFIBUS cable
The PROFIBUS cable is a two-stranded, twisted, and shielded cable.
Table 5-1
Features
Surge impedance
Loop resistance
Operating capacity
Attenuation
Permitted strand cross-section
Permissible cable diameter
Rules for laying
When you install a PROFIBUS cable, you must not:
● Twist
● Stretch
● Or compress it.
SIMOTION P320-4 E / P320-4 S
Commissioning and Hardware Installation Manual, 01/2015
Bus connector: Terminating resistor switched on and off
WARNING
Data exchange on the bus can be interrupted!
A bus segment must always be terminated with the terminating resistor at both ends. This
is not the case, for example, if the last node with a bus connector is de-energized. Because
the bus connector takes its voltage from the station, this terminating resistor is ineffective.
Make sure that the stations at which the terminating resistor is connected are always
energized.
Properties of the PROFIBUS cable
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
Connection
5.5 Connecting PROFIBUS
57