IOPort::Run RecvFailed 0 close 12" entry in LuaUPnP.log

Can anyone shed any light on the above error message? I’m polling a serial device using luup.io.write, getting replies back via , and occasionally my plug-in gets no response - which coincides with this message in the log.

Thanks.

If there’s any form of connectivity problem with the remote device, then a disconnect will occur, followed by a reconnect.

If you’re not actively writing to the connection it can take some time for this detect-and-reconnect to occur. If you are relatively idle in writing, then MiOS will heartbeat the device (using TCP Keep-alive, in newer builds).

If the device doesn’t send something back in that period (and it’s fairly long) then it will disconnect and reconnect also.

PS: Modified original post to remove the control/esc character prefixes that MiOS uses to colorize the log lines.

Thanks guessed. What do you mean by fairly long? This error comes up within 3-5 seconds of a poll.

No communications, not even a TCP KA packet, in 13 (from memory) minutes will trigger the behavior asyc. If a write() call returns failure at the is level, on a specific call, then the connection will also be reestablished.