Hi Anjana,
If you go to the B2B cockpit at the URL /b2bic and go into the EDI content manager what does your configuration look like for Ansi X. 12 -> Editor -> Control Key Scenario Association? Here is a sample from my system for instance although we are actually using TPM:
Also, what does the modules tab of your EDI Splitter sender channel look like?
Regards,
Ryan Crosby