Profibus and Profinet are industrial communications protocols
used extensively by Siemens control systems.
While they may sound similar,
don't let the names fool you
Profibus and Profinet are very different protocols
that use different cables and connectors.
Let's take a look at these protocols and learn how they differ from one another.
Before we get into today's video,
if you love our videos,
be sure to click the like button below.
and, make sure to click subscribe
and the bell to receive notifications of new RealPars videos.
This way you never miss another one!
Released in 1993, Profibus, or “ PROcess FIeld BUS,”
is a tried and true industrial communication protocol.
With over 50 million devices installed by the end of 2017,
it is a well established technology used in many different control applications.
A Profibus connection port may look very familiar to you
it looks just like a standard DB-9 serial connector.
While it may look the same, the underlying protocol is very different.
Most Profibus cable looks like this.
It is easily recognizable by its purple outer jacket.
Some Profibus connectors have a pass-through port on the back of the connector
so that you can daisy chain another device to the bus.
Note that both kinds of connectors have a red switch on the back.
This switch controls the Terminating Resistor.
The terminating resistor indicates the end of the ProfiBus network.
This switch must be set to the “on” position on the last device,
and “off” for every other device.
If these switches are set incorrectly, a bus fault will occur.
Each device on a Profibus network
must have a unique address, ranging from 1 to 127.
This means that up to 127 devices may reside on a single Profibus network.
For some devices, the address will be set using STEP7 or TIA Portal.
For others, the address must be configured
using dip switches located on the front of the device.
Profibus networks operate at speeds of 9600 bits per second to 12 megabits per second.
While Profibus cables may be up to 1000 meters long,
shorter cable lengths are required for higher data rates.
Profinet is a newer, Ethernet based industrial communications protocol.
The physical interface used for Profinet
is a standard RJ-45 Ethernet jack.
Profinet cables are easily recognizable by their green color.
While in some cases a standard Ethernet cable
may be used to connect two Profinet devices,
official Profinet cables should be used
as they contain robust shielding and are designed to function well
in harsh industrial environments.
Profinet operates at 100 megabits per second,
and cables may be up to 100 meters in length.
Due to its high speed operation
and a response time of less than 1 millisecond,
Profinet is ideal for high speed applications.
Because Profinet uses the same physical connection standards as Ethernet,
standard Ethernet switches can be used to expand your network.
Profinet devices have three different types of addresses:
an IP address, a MAC address, and a device name.
All Ethernet devices use IP addresses and MAC addresses,
but the device name is unique to Profinet devices.
As an automation engineer, you will be primarily concerned
with Device Names and IP addresses
as you configure your Profinet networks.
Due to its higher speed and greater flexibility,
Profinet is becoming the preferred communications protocol
for industrial application.
Both protocols are widely used today,
and being familiar with both of them
will be essential to your job as a controls engineer.
Want to learn PLC programming in an easy to understand format
and take your career to the next level?
Head on over to realpars.com