From Xojo Documentation
Sends a message consisting of command and data to the machine having the IP address specified by IPAddress.
Effective with 2017r3, the command parameter is Int32 instead of Integer to prevent incorrect behavior in 64-bit apps.
The text encoding is not sent to the other application. So if you want to preserve text encoding, you should use ConvertEncoding to e.g. UTF-8 before sending the string and use DefineEncoding when you receive a message to restore the text encoding.