I have a Connect Me (DC-ME-01T-S) that uses UDP broadcast to communicate. Upon power-up, the system works as expected for a short time, with the host communicating correctly. After this seemingly random time, the module shuts down (or freezes) and no longer appears on the network. It must be hard-reset for it to continue working.
The host responds with 10 or 12 bytes, however the last packet sent from the module before shutdown is exactly one byte short. The missing byte is always the fourth byte. The firmware is up-to-date.
POST was up-to-date, and EOS was 82000857_F6 but is now the 82001116_K4. Thanks for pointing out the correct firmware, but the problem still remains on three modules with this firmware.
I fell upon the solution and I’ll post it here in hopes that someone else may need it.
Firmware was not the issue. Documentation was. The module was/is working correctly. The problem is the default flow control setting for the serial device is software.
The solution is to set flow control to none.
My serial device uses the fourth byte to transmit seconds, and the module would fail upon sending 12 (hex). 0x12 (DC2), coupled with a previous 0x11 (DC1) indicate a block-mode handshake. The module would hang after this waiting for another DC1 before sending, but would never receive it because the serial device only responds to a poll. It became a vicious cycle where the poll response froze the module but would never restart it.
Beware of default settings and poor documentation.