I am trying to configure Client SDK as a client on a Linux Server. I already have Client SDK configured and working on the server with the database resident. I am trying to configure the second linux server which is running PHP to connect to the first servers database. I can see how i configure PHP to call informix but all the documentation appears to expect the database to reside on the same server as the Client SDK product. Is this a logical approach or am I missing something. Any thoughts would be much appreciated.

Cheers

Not true.
You have to fill in the correct parameters on the odbc.ini:

INFORMIXSERVER (tcp connection informixserver, check sqlhosts file in $INFORMIXDIR/etc)
HOST and portnumber
USERNAME/PWD