TDTPy is a Python wrapper around Tucker-Davis Technologies ActiveX library [PDF link] (known as RPcoX) for communicating with their System 3 hardware (e.g. the RP2.1, RX6, RZ6, etc.). In addition to the standard operations (loading circuits, configuring tags and reading/writing to hardware buffers), TDTPy offers a number of high-level features that are not included in the ActiveX library:

• Handling type conversion between analog and digital units (e.g. converting seconds to number of DSP cycles based on the CPU frequency of the hardware).
• Remote procedure call (RPC) server for allowing multiple processes and/or programs to communicate with the hardware across the same connection. The drivers provided by TDT do not handle concurrency issues. To handle these issues, we have created a RPC server that handles concurrency issues, allowing multiple programs to talk to the hardware simultaneously. The programs can either run on the same computer or on a separate computer.
• If you use the RPC server, your client code can run on any platform (e.g. Mac OSX, Unix, Solaris, etc); however, the server must run on a Windows-based computer.
• Simple reads and writes. The hardware buffers are implemented as "ring buffers" with various features such as multichannel storage and data compression. TDTPy automatically detects the configuration of the hardware buffer and returns a buffer object (DSPBuffer) that you can read/write to without having to deal with the intricacies of the hardware buffer itself.
• Robust error handling. Some methods in the ActiveX library will fail silently (e.g. if you try to access a nonexistent tag, attempt to write more data than the hardware buffer can hold, or wire up a tag to a static port). When the RPvds circuit is first loaded to the hardware, TDTPy will inspect the microcode (i.e. the RPvds circuit) and store some information about the tags and buffers available. All subsequent operations are validated against this metadata before being passed to the ActiveX library. If an invalid operation is attempted, a DSPError is raised with the appropriate message.