Lika H 58 Series, Руководство пользователя

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Hx58x EtherCAT®
•
Logical Address = the slave is not provided with its own individual address,
but it can read and write data in a section of the total memory space
available (4 Gigabytes).
5.1.6 Communication mode
Lika encoders with EtherCAT interface support the following operating modes:
•
FreeRun: asynchronous mode;
•
SM3 event: synchronous mode;
•
DC: distributed clock synchronization mode (synchronous mode).
For a system that requires high performances in real time (closed-loop
applications) we suggest using DC mode; if real time requirements are not so
mandatory SM3 or Freerun modes can be used instead.
A reference parameter is the “Jitter”: it represents the temporal fluctuation of
the instant data sampling; in other words data sampled by the micro-controller
is available in ECAT DPRAM memory after a certain time and the measure of the
variability over time is the “jitter”.
FreeRun
Asynchronous mode; encoder position is sampled directly from EtherCAT frame
sent by the master; position update is performed by an internal timer of the
controller every 100 microseconds.
This operating mode has a high sampling jitter (up to 100 microseconds) and
can be chosen only when cycle times are quite longer than the jitter if we want
to ensure a sufficient real-time system performance.
Description Min Typ Max
Jitter 0 100
µ
sec
Cycle Time 1000 64000
µ
sec
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0x1C33:02 (Cycle Time)
0x1C33:05 (Min Cycle Time)
0x1C33:06
(Calc & Copy)
Local Timer Local Timer
Input Latch
Local
Timer
Local
Timer
Local
Timer
Local
Timer
Local
Timer
Local
Timer
Frame N Frame N+1