Hi,
You can define a scenario step using HTTP Inbound and using B1 object call atom.
B1i handles incoming HTTP calls as synchronous calls and will give you the result of the B1 DI API message, if the SALES Order creation has been successful.
You can compare it with the standard mobile scenarios included in package sap.B1Mobile:
Send your JSON format against B1i and transform the incoming format into B1 DI API Sales Order format.
Best regards
Bastian
P.S.: since B1 9.1 pl09 as an alternative to the DI API the Service Layer connection is supported for B1 on HANA systems.