Keywords: Process Control, Components and Devices, Robotic and Automation Systems
Abstract: Servo is a core component in a control system. In experimental physics research, digital servos are widely used to control and lock the experiment environment to an expected state. Leibrandt et la. (2015) from NIST (the National Institute of Standards and Technology at the U.S.) published a general-purpose Digital Servo to support quantum physics experiments. The servo uses an Opal Kelly XEM6010(Spartan-6) FPGA board as the controlling and digital signal processing component, a home-made daughter board to connect the FPGA board to a 2-channel 16-bit 125MSPS ADC(LTC2195), a 2-channel 16-bit 500MSPS fast DAC(AD9783), and a 20-bit slow DAC(AD5791). The signal processing is implemented by IIRs on the FPGA. Just by changing the parameters of the IIRs, the users can achieve their expected system transfer response. The design of the hardware (the daughter board), the firmware (FPGA logic), and the software (PC GUI/API) are kindly open sourced by the authors. We want to implement this digital servo, but the XEM6010 board is out-of-life. Although the XEM7010 board is the migration replacement suggested by the maker, it is not completely compatible with XEM6010 as 1, a used I/O standard is different. 2, some used Xilinx primitives and IPs are different. We have modified the hardware and firmware designs to successfully migrate the servo to XEM7010. Some considerations and solutions can be shared in the workshop.