Lenze E94AYCEO - Internal Switch Latency

Lenze · E94AYCEO communication module (EtherNet/IP™) · Communication Manual · DMS 3.0 EN · 12/2013 · TD17 18
4Technical data
4.4 Internal switch latency
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4.4 Internal switch latency
The integrated 2-port switch causes runtime delays. For "store-and-forward" and 100 Mbps, these
runtime delays can be calculated as follows.
• Runtime delay for an output data packet of the scanners incl.
32-bit "Run/Idle header" with 16-
bit sequence counter:
• Runtime delay for an output data packet of an adapter without
32/bit "Run/Idle header":
Example
Delay of an output data packet of the scanners with 8 output data words (16 bytes):
• ((66 permanent bytes + 16 bytes) x 8 x 10 nsec) + 4 μsec
• (82 bytes x 8 x 10 nsec) + 4 μsec
• 6.56 μsec + 4 μsec = 10.56 μsec
Runtime delay = ((66 permanent bytes + I/O data in bytes) x 8 x 10 nsec) + 4 μsec
Runtime delay = ((62 permanent bytes + I/O data in bytes) x 8 x 10 nsec) + 4 μsec
 Note!
The use of external switches can also lead to runtime delays. Depending on the system
constellation, it may be useful to create a star topology or a line/mix topology.
Network topology
( 26)