This article describes the proposal for an architecture that allows to easily connect different devices or modules to a system for computer integrated surgery (CIS). This would allow the reuse of expensive CIS devices like robots. Yet, in contrast to other surgical robot systems, this architecture does not require a robot - it just supports its use. Therefore, a robot and its attached tool are distinguished as two separate devices. All devices in this architecture have knowledge about themselves and thus hardly depend on other devices. The article motivates and describes this architecture and explains an example implementation.