Welcome to MinutePROFINET.
My name is Michael Bowne, and I am part of PI North America, a non-profit member-supported
organization.
We aim to promote and educate the public on industrial automation and networking technologies.
In today's video we will list the top five mistakes made in PROFIBUS networks and give
you some tips on how to prevent them.
--Number 5: Wrong cable-- Do not utilize telephone or other consumer-market off-the-shelf cables
in a PROFIBUS network.
Such cables are not built to survive in industrial facilities where PROFIBUS is used.
PROFIBUS installations should employ shielded twisted pair cables that meet PROFIBUS guidelines.
Dozens of vendors offer PROFIBUS cables which often come with a purple jacketing and comply
with ruggedized specifications that have been set by PI.
--Number 4: Improper distance for baud rate-- PROFIBUS DP networks can run at different
baud rates, depending on the application.
The higher the baud rate, the shorter the recommended maximum length for cable segments.
Utilizing proper cable segments prevents significant signal attenuation and distortion.
For example, at 1.5 and 12 Mbit/s baud rates, the maximum recommended segment length is
200m and 100m, respectively.
Never exceed the maximum recommended cable length.
Always check your installation against the PROFIBUS Installation Guidelines and confirm
that cable lengths are appropriate.
--Number 3: PROFIBUS cable installed too close to power cables-- PROFIBUS, like any digital
network, is susceptible to electromagnetic interference.
To prevent data corruption due to EMI, avoid running data and power cables right next to
each other.
Maintain the separation distances specified in the PROFIBUS Installation Guidelines and
if they need to cross one another, it should be at right angles.
If data cables need to run in an area where very strong interference is unavoidable, consider
fiber optic cables instead of copper, as they are immune to electromagnetic interference.
--Number 2: Improper shielding and grounding-- The PROFIBUS Installation Guideline recommends
that cable shielding be grounded at multiple points or both ends of a segment.
This protects against high-frequency interference and provides a low impedance path to ground
in case of any pickup.
Ungrounded shielding is ineffective.
With PROFIBUS it’s easy: simply ensure that connectors are properly installed.
That’s it.
From there, nearly all devices provide continuity from the metal shroud on the plug, through
the socket, to a ground lug or metallic DIN rail connection.
Finally, the most common problem in PROFIBUS networks is: --Lack of or improper termination--
PROFIBUS networks must have termination resistors engaged at the beginning and end of each segment
in order to minimize signal reflections.
It is easily implemented via built-in switchable termination in connectors, in devices, or
via an active termination box.
As you can see, most of the problems that crop up in a PROFIBUS network have nothing
to do with the protocol itself -but with the installation of the network.
We recently launched a PROFIBUS Online Training Course that covers a complete overview of
PROFIBUS DP and PA network design, commissioning, installation, maintenance, and troubleshooting.
You can take the course at us.profinet.com/profibusonline.
And as always, thank you for watching, please feel free to comment below, share your feedback,
and any questions.