Multimaster functionality allows user to control several EtherCAT® buses from the same target system simultaneously. Master API gives an opportunity to create several master instances inside one process (or several processes). Each master instance has its own handle, so resources such as network interfaces and timers are used without conflicts and there is no confusion when using API calls.


Multimaster functionality may be implemented in two ways:

  1. Independent Master’s resources: several Master instances on the same target use only their own resources and do not refer to each other. In this case, when one of the Master instances fails the rest of them may work properly.
  2. The same Master’s resource: several Master instances on the same target use the same resource simultaneously. In this case you do not have to create the source and implement some changes in it for each Master instance, you do it just one time.

Multimaster functionality is available in KPA EtherCAT Master v1.6 or higher and is provided as feature pack that should be additionally activated through license file.

To configure proper DC synchronization for several Masters, one of them should be synchronized with slave (set the slave as a Reference clock). The rest of Masters would work in External synchronization mode with “Master” as an external synchronization device.