Integration between Adabas D and Adabas C

We have a system which uses Adabas D (interface: Adabas SQL) that needs to interact with another system (Mainframe, Language: Natural) which utilizes Adabas C as back-end. We’ve have tried to install a middleware (Connix) to solve the problem but it never worked. If you know any tools which can help in integrating these platforms, I would be glad to get your suggestions.

Kind Regards