CS400 is not compatible with the blue ICP modules. Therefore, when ordering an upgrade package and you have:

7067 - 7 channel relay module:

You will need A-IO-BASICKIT+ A-IO-2R-NO (x4):

You have: 7043 - 16 channel open collector module:

You will need A-IO-BASICKIT +  A-IO-16DO :

A-IO-BASICKIT is always supplied with a supply module 750-602. Although it is not needed for the relay output, it is useful for further expansion (AO or DO).