Datasheet
5
161
EX250
EX600
EX510
EX500
Subject to change
FIELDBUS
Fieldbus system
By using eldbus technology it allows you to congure and control easily,
safely and quickly decentralized islands. Installation costs are low when you
control the number of solenoid valves with only a 2-wire transmission cable.
M
any have discovered the benets of control
valves and take in the sensor signals through se-
rial communication (eldbus). The technology is
becoming, more or less standard in factory automation
with benets such as:
■ Reduced wiring
■ Quick and easy installation
■ Simplied error nding
■ Easy to extend application
■ Simplied drawings
■ Diagnostic features
User value will appear in a more efcient production,
improved quality and overall a more exible and cost ef-
fective application.
What is eldbus really?
In a conventional system the handling of signals to the
PLC are done through adjacent I/O cards. This means
that the signals must be connected individually in parallel
between the PLC and eld modules, which in turn leads
to huge cables that are difcult to manage and therefore
makes troubleshooting more difcult.
Fieldbus technology is a way to transmit analogue
and digital signals in a serial way between one control
system (PLC, PC) to different eld units, (sensors, valves
etc). Most systems communicate with a 2-wire cable
(shielded, twisted pair), but solutions with beroptics are
also present, for example in environments with a lot of
electrical noice.
Which protocol should I choose?
In the late 1980’s there were hundreds of different eld-
bus languages (protocols) who unfortunately could not
communicate with each other.
Thankfully, the market has been consolidated to
todays’ 20 some protocols that are trending, and are
supported by the major automation suppliers. Some of
these are focused on real estate automation, or are spe-
cic eldbuses for environments with EX–requirements
etc.
For traditional factory automation, there is about 10
protocols, from which the most common are: PROFI-
BUS DP, DeviceNet, EtherNet/IP, EtherCAT and AS–I.
Between these there are differences in speed on the bus,
conguration, network structure, etc.
To nd out which eldbus protocol that is most suit-
able for your application, you can contact your local
SMC technical support engineer.
Conventional
technology
Fieldbus
technology