USB Ethernet support for EtherCAT machines

1. XL200 controllers configured for EtherCAT now get a direct, inexpensive network connection. On these machines the Ethernet port is dedicated to running the drives, so until now an Eclipse connection required routing through RS485 — which in practice usually meant purchasing an expensive RS485-to-Ethernet converter. With this change, plugging a low-cost USB-to-Ethernet adapter into the controller's USB port puts the machine on the network directly, and Eclipse communicates through it exactly as it does on a standard machine — no converter hardware required. Nothing changes for non-EtherCAT machines — their built-in Ethernet port works as it always has, and this was re-tested to confirm it.

2. Setup works the same way customers already know. The IP address, subnet, and gateway are entered on the same Ethernet settings screens used today, and changes take effect immediately without restarting the machine. The adapter should be plugged in when the machine powers up. Removing it while the machine runs will not disturb the machine or the drives; plugging it back in will usually restore the connection on its own, but a power cycle may occasionally be needed.

3. A long-standing hidden problem in the controller's USB system was found and fixed. The USB hardware was never being told to watch for a device being unplugged, so an unplug went completely unnoticed by the software — the root cause of the connection failing to recover. This flaw has been present since the original vendor software shipped and would have affected any future product using USB on this processor family. It is now fixed for all of them.

4. Several smaller reliability problems were fixed along the way, including one where an internal timing miscalculation could quietly consume most of a background task's time, and one that could have corrupted memory when an unplugged device left an unfinished request behind.

5. The controller now reports much more of what it is doing over its diagnostic output — which network mode the display processor selected, when the network settings arrive, and each step of a USB device being connected or removed. These messages were essential in finding the problems above and will make future field issues much faster to diagnose.

Supported adapters currently: USB 3.0 gigabit adapters using the AX88179 chip. Support for the AX88772 family (the originally planned adapter) is prepared and will be completed when reliable hardware is available.