Download EPL-Router sorgt für Transparenz und Durchgängigkeit

Technical Paper
Ethernet Powerlink-Router guarantees transparency and
continuity
Problem-free access from anywhere
Ethernet is becoming more and more established, also in the field of
automation as a powerful communication system in different versions.
Ethernet Powerlink is an Industrial Ethernet system that has proven
itself in many cases already. The Ethernet Powerlink Router by
Deutschmann Automation takes care of the seamless integration of
Ethernet Powerlink into superior Ethernet TCP/IP-networks.
Ethernet Powerlink is a protocol extension to the Ethernet standard according
to IEEE 802.3, in order to transfer real-time data in the time range of
microseconds. It was developed considering standard conformity and it
extends Ethernet by a mixed polling- and time slice-mechanism: With it the
transfer of time-critical data is guaranteed within short isochronous cycles with
configurable runtime performance as well as the time synchronization of all
network nodes in the time range of sub-microseconds. The transfer of the less
time-critical data traffic takes place in the reserved asynchronous channel.
Current implementations of Ethernet Powerlink achieve cycle times of less
then 200µs and a time accuracy (Jitter) of less then 1µs.
Collisions on the Ethernet have to be avoided in order to guarantee the realtime. For that purpose the data transmission is controlled by means of a
special node, the „Managing Node“ (MN). The other devices, the so-called
„Controlled Nodes“ (CN) are only allowed to send if the MN asks them. Each
cycle starts with a special telegram, the „Start of Cyclic“ (SoC). After that each
node is prompted by the MN with a „Poll Request“ (PReq), whereon the CN
replies with a „Poll Response“ (PRes). The PRes are sent by Ethernetmulticast. That way all others can also hear the response. A crosswise datatraffic between the CNs is possible. It is not necessary to poll every device in
each cycle. Telegrams can be transferred by PDO and SDO.
Seamless integration of Ethernet Powerlink and Ethernet TCP/IP
The Ethernet Powerlink, originally developed by B&R was disclosed in 2001
and it was introduced to the user and vendor group EPSG (Ethernet Powerlink
Standardization Group). There it is being further developed and specified as
open standard. In 2003 it achieved series-production-readiness. Currently
throughout the world thousands of end users have more than 210000 nodes
installed in more than 28000 machines. More than 200 mechanical engineers
bank on Ethernet Powerlink. Soon Ethernet Powerlink will be part of the
standards IEC 61748-2 and IEC 61158. The original physical level is
100Base-X Fast Ethernet (IEEE 800.3). Since the end of 2006 Ethernet
Powerlink supports with Gigabit Ethernet a transfer rate which is ten times as
high (1000 Mbit/s). The migration to Gbit-Ethernet does not present a problem
- Ethernet Powerlink does not require proprietary ASICs.
Ethernet Powerlink is mostly used, where a fast machine communication is
required. It is suitable for all critical control-oriented requirements. Ethernet
TCP/IP is mostly used as superior industrial network. Since Ethernet
Powerlink also allows the less time-critical asynchronous transfer of additional
information, it is suggested to use it also for the information transmission, for
instance for diagnosis- and parameterization means. Consequently the
machine and plant engineer only needs communication medium based on
standard components.
The Ethernet Powerlink-Router by Deutschmann Automation was developed
for the seamless integration of an Ethernet Powerlink segment within a
machine into the industrial network and with it being able to access the realtime controllers transparently from a remote station with Ethernet Powerlink.
For this reason it is an important component to create a complete continuity on
basis of Ethernet.
Router-version appropriate for industrial use
The Ethernet Powerlink-Router is equipped with two Ethernet-ports and
connects two networks on IP-level. For this purpose it requires two IEEE802.3-compliant network accesses. The real-time port is connected with an
Ethernet-Powerlink-segment. The second port is the interface to an IPnetwork, the so-called generic or legacy Ethernet. On the Ethernet Powerlinkside the Ethernet Powerlink-Router acts like any other Ethernet Powerlinkparticipant and has the communication profile for a Controlled Node (CN)
implemented. The Router works with the 4NetOS-system software by SND
and the Ethernet Powerlink V2.0 protocol stack. Through an integrated HTMLpage the NAT-Routing can be set by means of any web browser. For start-up
tests a simple MN-function is available on the Ethernet Powerlink-side. The
Ethernet Powerlink-Device monitor by port GmbH is using this MN-function in
order to carry out user-friendly configuration tasks at the network or the CNs.
The configuration tool features an excellent graphic operating guide and
moreover it is programmable.
Because of the compact dimensions of 23mm x 115mm x 100mm (w x d x h),
the DC-24V-supply and the easy mounting on DIN-rail the module can easily
be fitted into any switch cabinet The Router has an integrated grounding
available and it has a typical current consumption of 120 mA. The operating
temperature ranges between 0°C and +55°C.
The applications of the Ethernet Powerlink-Router are manifold. For example
an Ethernet-Powerlink network can be integrated into an Intranet or the
Internet with the Router. That way Powerlink-devices are accessible from any
PC in the office. The PC communicates with any Ethernet Powerlink-nodes via
TCP/IP (ping, HTTP, FTP etc.), without disturbing the real-time cycle. With it
simply remote maintenance concepts can be achieved for machines equipped
with Ethernet Powerlink..
The Ethernet Powerlink-Router can be applied especially for diagnosis of
plants.
This is possible by using the Ethernet Powerlink-Router together with a
special firmware developed by the company port and the network analysing
software Ethernet Powerlink-REport. In this operation mode the Ethernet
Powerlink-network is not influenced. Important variables and parameters,
mainly times are recorded, statistically edited and displayed. This extends
efficiently the existing self diagnosis already immanent in the Powerlink
protocol for plant safety purposes.
Further information from
Deutschmann Automation GmbH & Co. KG
Carl-Zeiss-Straße 8
D - 65520 Bad Camberg
Tel.: +49-(0) 64 34/94 33-0
Fax: +49-(0) 64 34/94 33-40
E-Mail: [email protected]
http://www.deutschmann.de
Caption:
Pictures UG Ethernet Powerlink xxx:: Ethernet Powerlink-Router from
Deutschmann Automation
Pictures reiter_1 und 2: Author: Michael M. Reiter, managing partner with
Deutschmann Automation, in charge of sales and marketing
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