Terminating Resistor; Gsd File - WEG CFW500 User Manual

connected to the network. Each repeater must also be included as a device connected to the segment, even
not occupying a network address.
It is recommended that the connection of all the devices present in the Profibus DP network be made coming
from the main bus. Generally, the Profibus network connector itself has an input and an output for the cable,
allowing the connection to be taken to the other network points. Derivations from the main bus are not
recommended, especially for baud rates higher or equal to 1.5Mbits/s.
The Profibus DP network cables must be laid separately (and far away if possible) from the power cables. All the
drives must be properly grounded, preferably at the same ground point. The Profibus cable shield must also be
grounded. The CFW500 Profibus board connector itself already has a connection with the protective ground
and, therefore, makes the connection of the shield to the ground when the Profibus cable is connected to the
drive. However a better connection, implemented by clamps that connect the shield to a ground point, is also
recommended.
3.6

TERMINATING RESISTOR

At each segment of the Profibus DP network, it is necessary to enable a terminating resistor at the end points of
the main bus. The use of specific Profibus network connectors with a switch to enable the resistor is
recommended, which must only be enabled (ON position) if the equipment is the first or the last element of the
segment. The DIP switches present in the communication module also can be used to enable the termination
resistors.
It is important to emphasize that in order to be possible to disconnect the element from the network without
impairing the bus, it becomes interesting the use of active terminations, which are elements that have only the
termination function. Therefore, any drive of the network can be disconnected from the bus without impairing
the termination.
3.7

GSD FILE

Each element of the Profibus DP network has an associated configuration file with the GSD extension. This file
describes the characteristics of each equipment and it is used by the Profibus DP network master configuration
tool. During the master configuration the GSD configuration file supplied with the equipment must be used.
1 It is necessary to connect the protective earth to the GND signal in the plug-module.
Phone: 800.894.0412 - Fax: 888.723.4773 - Web: www.ctiautomation.net - Email: info@ctiautomation.net
Figure 3.1: Connection example in a Profibus DP network
1