Defining Profibus-Dp In The Software; Shielding Precautions - Omron CS1W-PRM21 Operation Manual

Defining PROFIBUS-DP in the Software

2-4-4

Shielding Precautions

Cable shield connection
Inside cabinet
Ground Rail
Outside cabinet
2-5

Defining PROFIBUS-DP in the Software

Defining the Configuration
Downloading the
Configuration
PROFIBUS Organization recommends the following rule for data line color
codes: PROFIBUS cables in general will use the colors red and green for the
data lines, with the following assignment:
Data cable wire A - green
Data cable wire B - red
This rule applies to both the incoming and the outgoing data lines.
To ensure electro-magnetic compatibility (EMC), the shield of the cable should
be connected to the metal case of the plug connector.
If the Unit is installed in a control cabinet, the bus cable shield should be
brought into physical contact with a grounding rail using a grounding clamp or
similar device. The cable shield should continue in the cabinet right up to the
PROFIBUS device.
Ensure that the PLC and the control cabinet in which it is mounted have the
same ground potential by providing a large-area metallic contact to ground,
e.g. galvanized steel to ensure a good electrical connection. Grounding rails
should not be attached to painted surfaces.
For further information regarding PROFIBUS network installation, please refer
to "Installation Guideline for PROFIBUS-DP/FMS" (PNO Order No. 2.112),
which is available at every regional PROFIBUS Organization. The information
covers:
• Commissioning of PROFIBUS equipment.
• Testing the PROFIBUS cable and bus connectors.
• Determining loop resistance.
• Testing for correct bus termination.
• Determining the segment length and cable route.
• Other test methods.
• Example of an equipment report in the PROFIBUS guideline.
After making the physical connections of the network, the configuration then
has to be defined in the software. OMRON provides a dedicated PC-based
configuration program, called CX-Profibus, as well as the required DTMs for
this purpose. It must be used to:
• Define the master(s).
• Assign slaves to their respective master(s).
• Assign slaves to groups for broadcast/multicast messages.
• Enter bus parameters, e.g. baud rate, target rotation time etc.
The system must be downloaded to the master Unit after configuring it at the
PC. This is made possible by either connecting the serial COM port of the PC
to the CS1/CJ1 PLC with a serial interface cable, or use an ethernet connec-
tion between the PC and the CS1/CJ1 PLC via an ethernet unit.
Section 2-5
37