REST Sync Error Handling

Hi Experts,

I am working on error handling for REST-RFC sync scenario and i am using SAP REST sender channel.

I can throw fixed error(Error in PI text) exception from sender REST adapter for any error in JSON format using error handling tab but i need to capture original error from interface(like mapping error /communication error) and send it back to source system in JSON format.

At present by default PI giving error in HTTP format.

Please let me know how to capture error from PI and pass it to Source system in JSON format.

Thanks,

PT