Local TCP

[sparkz_alot]

I understand the the principle of TCP/IP is microsoft comms over the internet.

Well, not true. TCP/IP is an internet protocol, hence the 'IP', not a particular operating systems.

I can ping the unit locally but the packet data is lost.

If you are pinging the remote host and the data is lost, then the 'ping' is unsuccessful. Your description is tossing out a lot of terms, some relevant, some not and some ambiguous. For instance, when you say 'relay box', are you referring to a 'router'.

If I understand correctly, the setup is something like:

RF tagged critter ----> RF transceiver <----> Serial Modem <----> Raspberry Pi <----> Router <----> Internet <----> Server far far away

Note: The transceiver and modem can be one unit, depending on manufacturer.

Also bear in mind that TTL levels are 5Vdc for a '1' and '0' Vdc for a zero. The Raspberry Pi uses CMOS levels, which is 3.3 Vdc for a '1' and 0 Vdc for a '0'. Due to 'fudge' factors you may or may not be able to make a connection with the RF box from the Pi, but in all likely hood, you will overload the Pi when receiving the higher voltages from the RFbox.

If my little diagram is correct, you need to clarify which segment is failing, how it is failing and how Python fits in to the equation.