SEW-Eurodrive MOVIPRO Ethernet/IP - 6.3 Device Level Ring topology

6
Configuration and startup of EtherNet/IP™
Device Level Ring topology
Manual – MOVIPRO
®
with EtherNet/IP™ or Modbus/TCP Fieldbus Interface
46
6.3 Device Level Ring topology
6.3.1 Description
INFORMATION
The device supports announce telegrams only. Beacon telegrams on the fieldbus are
ignored and just forwarded by the device.
If a Device Level Ring topology (DLR topology) is used, 2 new telegrams are shown
on the fieldbus. Both telegrams can be used to detect single fault locations in the ring.
• Announce telegrams are sent cyclically every 1s.
No special hardware of the ring components is required to process the announce
telegrams.
The device supports announce telegrams only.
• The beacon telegrams are sent cyclically every 400μs by the ring supervisor.
A special hardware of the devices in the ring is required to process the beacon
telegrams.
The beacon telegrams are ignored and just forwarded by the device.
6.3.2 Ring fault detection
If Beacon telegrams that are sent to the first port of the ring supervisor are not re-
ceived by the second port of the ring supervisor, the ring supervisor detects a ring
fault.
If the telegrams do not run through the entire ring, the ring supervisor sends a non-
cyclical announce telegram. This non-cyclical announce telegram leads to a status
change of the EtherNet/IP™ interface. The network is automatically restored.
INFORMATION
Use less than 50 ring nodes in one DLR network. If more than 50 nodes are used in
one DLR network, you have to consider the following:
• The risk of faults in the DLR network increases.
• The times for fault rectification in a faulty DLR network increase.
→ If your application requires more than 50 modes, Rockwell Automation recom-
mends to split up the nodes in separate but linked DLR networks.
1)
1) See user guideline by Rockwell Automation "EtherNet/IP Embedded Switch Technology – Linear and
Device-level Ring Topologies", Appendix A
6.3.3 Rectifying ring faults
If a single fault location in the ring causes a fault and the rectification takes longer than
the fieldbus timeout interval, you can increase the fieldbus timeout (timeout interval)
by increasing the cycle time.
The timeout interval of the device is calculated as follows:
T RPI
Timeout
= × 32
T
Timeout
Timeout interval (fieldbus timeout) in ms
16998413/EN – 12/2016