© SICK AG • Presence Detection • Subject to change without notice • 8015887
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Operating instructions Register sensors RS25
Operation using Ethernet Powerlink
Time slot
Prq
SoC
PRs
SoA
MN
CN
async
I1
I2
I3
I7
I8
Fig. 28: Cyclical and acyclical data exchange,
EPL communication (Ethernet Powerlink)
async Acyclical data
CN Controlled nodes (network participants)
Ix I1 to I8, network participants
MN Managing node (participant that controls the data transfer)
PRq Poll request
PRs Poll response
SoC Start of cycle (start of the cyclical data cycle)
SoA Start of asynchronous (start of the acyclical data cycle)
TS Time slot (time window for responses)
10.3
NetTime
The Ethernet Powerlink NetTime is a remote clock that is supplied by the
PLC. The NetTime is responsible for the synchronization of the entire EPL
network. The NetTime guarantees that, in order to control the printing ma-
chine, all the time stamps to and from the sensor are consistent with the
other sensors or the data from the encoder for synchronization purposes.
10.4 Speed
Ethernet cables are used for the Ethernet Powerlink network. 10 Mbit or
1 Gbit networks are possible. Under ideal conditions, it is possible to con-
figure a cycle time of 400 µs and jitter (accuracy fluctuation) of less than or
equal to 1 µs. The standard cycle time is 1.2 ms.
10.5 Mapping (Object dictionary)
The data from the Ethernet Powerlink interface is mapped to objects. Each
object has several sub-indexes. The first sub-index manages the numbers
of the available sub-indexes. The other sub-indexes contain the data with
the read, write, and read/write access for the PLC of the Ethernet Powerlink
network. The data sizes (in bytes) of the sub-indexes are different.
