If a modules' intended usage is to be a sub-program CALLable from both online and batch, one should use a COBOL CALL, and the linkage would be that which is necessary for the subprogram to perform its function.
If a module is intended to be used in both batch and online, there is no need to reference EIB fields or DFHcomm fields. A copybook, defining the data necessary for the submodule, should be created and used.