Datalogic AMT58 Series Manual page 144

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.
Local Timer
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.
Local
Timer
Frame N
Description
Jitter
Cycle Time 1000
0x1C33:02 (Cycle Time)
0x1C33:06
(Calc & Copy)
Input Latch
Local Local Local
Timer Timer Timer
Frame N+1
Min Typ
0
64000
AMT58x-EC EtherCAT®
Local Timer
Local Local
Timer Timer
Max
100 µsec
µsec
35