Master Configuration
Double-click the 'EtherCAT' node in the PLANT which represents the master. Open the 'Settings' editor in the editors area.
- The editor displays the maximum number for connectable slave devices. This number depends on the EtherCAT Master and is specified in its device description.
- Enter a station name.
- Define the bus cycle time by selecting a value from the drop-down list.
The cycle time is the interval in which time-critical Process Data Objects (PDO) telegrams are transmitted in the EtherCAT network. The time intervals between two PDO telegrams are used for the exchange of Service Data Objects (SDOs).
- Mark the checkbox 'Create HC Group for Slaves' if you want the Master to assign each connected slave to a unique HotConnect group.
The HotConnect (HC) functionality allows to disconnect EtherCAT modules from the network during operation in terms of communication (e.g. by switching off or disconnecting the Ethernet line) or to insert them into the data traffic (e.g. by switching on or plugging in the Ethernet line).
- Specify the threshold alarm value for lost EtherCAT frames. If this threshold is exceeded, an alarm is created. Select a number from the drop-down list. The default value is '9'.
- Define the 'Update Task' of the master for system and global variables by selecting an entry from the drop-down list. The interval of the selected task then defines the rate at which the EtherCAT system variables (EC_*) and assigned global input/output variables are updated (that is, when the global input/output variables connected to the process data items are read/written).
The drop-down list provides tasks for selection that are defined in the 'Tasks and Events' editor (on the 'PLCnext' PLANT node).
Note
If no task is selected here, the update is done in an interval of 50 ms.