Fig. 21 Synchronization Mode: Slave (Sync Master: Balanced Pc Clock); Fig. 22 Synchronization Mode: Master - Beckhoff FC5101 Documentation

Parameterization and Commissioning
Fig. 21: Synchronization Mode: Slave (sync master: balanced PC clock)
Master
In master mode the card generates its time base locally. The SNYC telegram is crystal-precise on average.
The start of the TwinCAT task is specified by the card and is delayed by the shift time relative to the SYNC
telegram. In this mode, the shift time should be selected as large as possible. The function "Calculate Equi-
Times", which is triggered by clicking on the corresponding button after the mappings have been created,
helps to set the optimum shift time.
Fig. 22: Synchronization Mode: Master
Cycle Time
Displays the cycle time of the corresponding highest priority task. The display is updated when the mapping
is generated.
Watchdog Time
Here, a watchdog can be activated, which means that the FC510x enters STOP mode in the event of a PC
crash and also transfers all projected slaves to this state.
Sync-Cycle Multiplier
CANopen SYNC Cycle Time = (Task) Cycle Time x Sync-Cycle Multiplier. Event driven PDO
communications and cyclical synchronized PDO communication are frequently combined when used in
conjunction with CANopen. In order to be able to respond rapidly to an event, the TwinCAT task cycle time
has to be less than the CANopen SYNC cycle time. If the sync cycle multiplier is set to values > 1, the
TwinCAT task is called repeatedly before the SYNC telegram is sent again.
FC5101 and FC5102 Version: 2.0 25