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Operating Instructions
Chapter
3
UE4155
8010178/TF82/2010-03-05
© SICK AG • Industrial Safety Systems • Germany • All rights reserved
13
Subject to change without notice
Product description
PROFIsafe
PROFIsafe is an extension of the PROFIBUS DP protocol for safety technology. In the case
of PROFIsafe, the communication between the PROFIsafe users (“failsafe DP standard
slaves”) and the PROFIsafe master is protected against transmission errors and changes.
The UE4155 is a PROFIsafe device according to “PROFIsafe — Profile for Safety Techno-
logy”, V1.20 10/2002. This is why the UE4155 constantly expects a PROFIsafe master and
does not establish any communications with unsafe PROFIBUS DP masters.
You can find more information about PROFIBUS and PROFIsafe on the Internet at
www.profibus.com.
3.2.2
The principle of the bus node
The UE4155 bus node is a PROFIsafe slave. It collects the electrical signals from the
components connected to the UE4155 to form what is known as a
process image
. It sends
this to the PROFIsafe master in the form of a
PROFIsafe telegram
. The PROFIsafe master
copies the input data of the from the PROFIsafe telegram into the FPLC process image.
The FPLC evaluates the input process image. It then places the calculated output values
into the output process image. The PROFIsafe master transmits these output data to the
bus nodes in a PROFIsafe telegram.
The UE4155 transforms the incoming telegrams from the FPLC into electrical signals that
the connected components can process, e.g. by …
switching a non-safety-related output.
addressing specific functions of the connected devices.
Note
Fig. 1: Working principle of
the UE4155 bus node
E.g. laser sensing device
E.g. safety light
curtain C4000
E.g. sensor fitted with
contacts
PROFIsafe telegram
transports process
image of the PROFIsafe
slave
PROFIsafe compatible
FPLC