TCP-connection/Timout

When connecting over TCP, the printer closes the connection after 90 seconds inactivity with the reset flag. (Observed with Wireshark on my EPSON TM20II i use for my tests).

this cause that in BasePrinter -> Read() -> ReadByte(); throws an System.IO,IOException each 100ms (as you catch the exception with Thread.Sleep(100)) also Write() will throw the same exception.

here some logic is needed to check if the connection is lost. I have done some tests in my forked branch bug/connection : e.g. the connection can be checked as described here: https://stackoverflow.com/a/14925438/12648992 with a method for the network-Printer e.g.:

public override bool IsConnected()
        {
            return !((_socket.Poll(1000, SelectMode.SelectRead) && (_socket.Available == 0)) || !_socket.Connected);
        }

also the System.IO.IOException exception of BasePrinters Read() might be handled as lost connection.

however with my changes i can only handle the dropped connection by the printer. handle issues with the network like unplug eth-cable on the printer or restart raises additional issues (TCP-connection stayes open while the printer is gone)

[lukevp]

@oachkatzalschwoaf @kodejack thanks for coordinating this, I really appreciate it! I don’t have a network printer so I’m glad you all were able to get this fixed and merged in.

[oachkatzalschwoaf]

fixed in master