Error: Red Triangle on EtherCAT Axes / Devices when Modbus or Profinet Connects

Symptom: Red triangle error on EtherCAT axes/devices when ModBus or ProfiNet connect

Cause: The Modbus and ProfiNet tasks when enabled can cause an increase in demand in the processor on the PAC. If the EtherCAT master task is set to 500us, when the ModbusTCP and ProfiNet fieldbuses connect, this can increase (~1300us) causing a timeout.

Remedy:

As Modbus and ProfiNet are only exchanging tag/variable information and not motion and other time critical data, these should be set on their own task.

The default task in a new project is EtherCAT_Master. A second task should be created within the Task Manager. This can be a cyclic task and this can be set to it's own cyclic update rate. Typical would be 100-200ms. By default when the ModbusTCP or ProfiNet devices are added, the bus cycle task is set to EtherCAT_Master since this is the only task in a new project. After creating this new task, then go into the IO Mapping to the Bus cycle options and reassign to the new task. This example shows it set to MainTask:

11/14jh

keywords: Netjack Modicon SiemensS7 plc