Sending Pending Messages

In situations of communication failure with the SiTef server, CliSiTef will automatically send any
remaining data (e.g. commit, uncommit and undo data) only in the next
POS transaction.
However, it may take some time before the next transaction is initiated at the station.
At times when the POS is at rest or “idle”, the automation can use the following routine
to force the library to offload commit, uncommit, and undo messages to the SiTef server.

int DescarregaMensagens (void)

Upon return, the routine returns *0 if it managed to download all messages and non-zero if it occurs
There is an error making it impossible to send them.