Real-time communication for ground testing of cryogenic engines and stages of Indian space missions

The method of implementation of EtherCAT Automation Protocol (EAP) for real-time communication between the control system and the data acquisition system in cryogenic test facilities is discussed here. The different data transfer modes, the frame structure etc. are highlighted. The performance of EtherCAT communication is evaluated and the results are presented. Publisher-Subscriber communication mode is configured for the communication between the control system and data acquisition system. It is found that the transfer of 1024 byte data from data acquisition system to the control system can be realized every 10ms by defining an EAP stack in both the controllers.