I/O Idle Task

The I/O Idle Task handles acyclic communication for fieldbuses, so it is responsible for:

• the State Machine of the EtherCAT Devices
• CoE and SoE communication
• Reading or setting parameters via AOE
• Mailbox communication
• Acyclic diagnostics from EtherCAT (e.g. status queries)

The I/O Idle Task is a cyclic task, but is not used for cyclic I/O communication (process data exchange). It therefore makes sense in most cases to select the priority so that it is executed after the PLC and motion tasks. As this is also acyclic communication, cycle timeouts of these tasks are generally not significant.

Since TwinCAT version 3.1.4026, it has been possible to use multiple I/O Idle Tasks (one per EtherCAT master). The choice of I/O Idle Task is made via the adapter settings of the EtherCAT master.