Robot Control PCI Express Card
Three generations of robot control cards have been developed for this client - PCI and two generations of COM Express (PCI Express in the COM Express form factor). The FPGA (originally a Virtex-5, now a Spartan-6) provides 10 Controller Area Network interfaces which communicate to all of the robot axes, as well as two serial ports, an NVSRAM interface, and an SDLC interface to an Inertial Measurement Unit (IMU), a watchdog timer, and other I/O. A custom DMA engine is used to DMA the CAN and IMU data to host memory across the PCI Express interface.
The Real Time Data Interface
The RDI is a custom PCI card used for real time distributed motion control systems. Verien created a link protocol which allowed for deterministic latency, as well as the ability to schedule DMA-based real-time transfers. A special clocking scheme is a part of this protocol which allowed nanosecond-class box-to-box synchronization for distributed real-time control operations. Transfers can be either reliable (acknowledged and retried in hardware) or UDP-style with a sequence number provided at the destination.The RDI card provides four 500 Mbit/sec links for reliable packet communications over CAT cable and eight linked-list DMA engines which allow real-time scheduled transfers. These communicate to the I/O cards at the end points which read position and other sensor information and drive the motors.