atp edition Einsatz robotergeführter Patientenliegen (Vorschau)

HAUPTBEITRAG | AUTOMATION 2014
FIGURE 5: OPC UA
communication with
the cloud
FIGURE 7:
Response time
for a prototype
of a Soft-PLC in
a private cloud
FIGURE 6:
Soft-PLC in the
cloud controlling
a simulated
device on the site
– this means in these cases the embedded device sends
requests to the PC.
OPC.TCP (SEC) on Raspberry was used in Basic128Rsa15
mode – instead of the default Basic256
mode, which did not work. The test labelled with
“OPC.TCP Raspberry (local)” shows the performance
if the requests are sent only within the Raspberry
(local-only requests with no network communication
involved / similar to the local PC scenario). HTTPS
on Raspberry did not seem to work properly as it showed
latencies of up to 4.7 seconds. In the reverse direction
it worked, but also with relatively high latencies
around 33 ms. On Android, HTTPS was excluded
due to problems with overlapping namespaces with
the Android SDK.
The tests on Android showed similar behaviour –
with a somewhat higher latency, which might be caused
by the Wi-Fi connectivity.
AUTHORS
Dr. JOHANNES SCHMITT
(born 1979) is Scientist in
the group Intelligent
Devices at ABB Corporate
Research. His research
focusses communication
and especially middleware
technologies for automation
systems. He also investigates
the use of OPC UA on embedded or
mobile devices up to cloud based systems.
ABB AG Forschungszentrum,
Wallstadter Str. 59, D-68526 Ladenburg,
Tel. +49 (0) 6203 71 60 08,
E-Mail: Johannes.O.Schmitt@de.abb.com
Dr. THOMAS GOLD-
SCHMIDT (born 1982) is a
Principal Scientist at the
ABB Corporate Research in
Germany. He focuses on
domain-specific language
engineering and software
architectures in the
automation domain.
Thomas holds a PhD in computer science from
the Karlsruhe Institute of Technology, Germany.
ABB AG Forschungszentrum,
Wallstadter Str. 59, D-68526 Ladenburg,
Tel. +49 (0) 6203 71 61 34,
E-Mail: thomas.goldschmidt@de.abb.com
38
atp edition
7-8 / 2014