XMLHttpRequest Send Command Size Limitations RCM4300

"[email protected] [rabbit-semi]" <[email protected]> 19 Feb 2016 02:01:25 -0800
Newsgroups gmane.comp.hardware.rabbit-semiconductor
Message-ID <[email protected]>
Good day,
I would like to know what the size limitation is when using XMLHttpRequest() "send" command?
I have been through the documentation and can't seem to find any (MACROS) settings for this?

I can successfully send a small number of characters, but the data is truncated if I go above 256bytes.
I'm using the RCM4300 in a web server application.
Ideally I would like to send up to 30kbytes at a time. This is being used in a data logging application.

Thanks in advance.
Mike