We are looking to setting up a fault tolerant solution for software that monitors CNC machining equipment. The proprietary software uses TCP/IP, serial over TCP/IP and an external SQL server database to monitor and report on the machining process. I am concerned that the failover delay, while not long enough to bother a human being, may cause some timeout issues when communicating with the manufacturing equipment. If an unplanned failover will cause timing issues, fault tolerance will not be a reliable solution.