Short description of the Easygen3000XT redundant network communication

Basics

• The system is not PRP, but a Woodward own system. It resembles PRP, however.
• Every device sends cyclically UDP messages with process data on both ports simultaneously
• Cycle time is typically 80msec
• The data on both ports are identical
• Messages are broadcast messages and every device listens to all messages from all other devices on both ports
• Every UDP message has a sequence number
• When a device receives a UDP message on either of its two ports
  • If a message with the same sequence number was already received on the other port, it is discarded
  • Otherwise the messages is processed
• There is a teach in mechanism at setup, to tell all device in a system who are the others in the system and from whom messages are to be expected
• There are timeout monitorings

Fail Over

• The system tolerates disruptions/break of one Ethernet line. As long there is at least one of the both lines active, there will be no influence on operation.
• There is no fail over mechanism if a device completely fails, and a second (until then dormant) device would have to take over.