We have an application using a Mitsubishi L02CPU-P with a built in ethernet module.
At one time the TCP/IP interface became irresponsive and a hard reset was required.
The device is configured for binary communication and works fine using a GOT therminal and also operates fine when queried from a GX Works application.
During debugging of a custom MELSEC application the TCP/IP interface stopped responding and could no longer be located using GX Works and the GOT terminal also lost contact.
The L02CPU-P continued running the control application, but could no longer be contacted. The only way to recover was using the L02CPU-P reset button.
I have heard developers being restrictive using the TCP/IP interface remotely over VPN and unstable connection due to the risk of hanging the device and not being able to recover without a personal visit to the device.
Any experience from L02CPU-P devices requiring hard reset to come "online" again? Or does it enter some default state due to some internal exception handling?