Chemical Engineering August 2022 - 33

www.ekato.com
FIGURE 3. The chart shows a comparison of field-level technologies in process plants
connected in line or in a ring formation
using copper cables or fiberoptic
lines.
Trunk-and-spur topologies require
an additional APL power switch,
which supplies power from the central
control room to the field via a
powered trunk line. Both APL field
switches and APL field devices are
powered via this APL trunk. No other
field-level power supply is needed.
There is no general rule about
which topology shall be preferred.
It always depends on the plant design,
communication requirements
and the environment. In general, the
star topology provides more flexibility
in terms of redundancy and number
of devices per segment. The trunkand-spur
topology might be more
relevant if additional power supply in
the field requires a lot of effort.
Ethernet-APL offers a path for
migrating a brownfield plant to this
new technology. Power conditioners,
junction boxes and field barriers
must be replaced with APL switches.
Any existing cable that does not
meet the specifications for EthernetAPL
will have to be replaced as well.
The well-known Fieldbus Type A
cables, which meet the required APL
cable characteristics, are the preferred
cable type for Ethernet-APL
installations. Specific SPE cables for
10BASE-T1L are also suitable.
APL switch vendors are providing
the possibility to connect devices
using either Profibus PA or ProfinetAPL
at the same APL field switch.
This means that the Ethernet-APL
technology can be installed on site
even if some instruments are not yet
available with an APL interface.
Integration into higher
applications
Ethernet-APL is a new physical layer
for the field level connectivity. According
to the ISO OSI model, the
upper layers are independent of this
physical layer, which means that any
industrial Ethernet protocol can be
implemented on top of Ethernet-APL.
This includes Profinet, EtherNet/IP or
Modbus TCP. These protocols and
their functionalities are important for
upper-layer integrations.
Profinet. Profinet is a well-established
industrial Ethernet protocol
used in many industries already. In
combination
with Ethernet-APL,
Profinet will also fully enter the process
industries. The GSD (general
station description) file is the Profinet
device driver that is used for the integration
to distributed control system
(DCS). This file is stored on each
device, which makes it easy to integrate
new devices onto the network.
Profinet PA Profile 4 offers additional
benefits, such as harmonized inteCHEMICAL
ENGINEERING WWW.CHEMENGONLINE.COM
AUGUST 2022
MIXING SOLUTIONS FOR
PLASTICS RECYCLING
* Customized reactor concepts
* EKATO PARAVISC & PARASEG
for demanding mixing tasks
* Optimizing upstream mixing
* CFD & FEM expertise
* Safe scale-up to production size
* Joint development agreements
for new processes
VISIT US!
Hall 11
Booth A65
Your partner for
advanced mixing solutions:
Phone: 1 201 825 4684 Ext. 205
info@ekato.com
For details visit adlinks.chemengonline.com/ 82584-14
33
http://http:// http://adlinks.chemengonline.com/82584-14 http://WWW.CHEMENGONLINE.COM
Chemical Engineering August 2022

Table of Contents for the Digital Edition of Chemical Engineering August 2022
