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README.md

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+Digital Phase-locked-loop software for Locking a Frequency Comb using a Red Pitaya
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+This software runs on the Red Pitaya with a user interface written in Python that runs on your control PC.
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+The firmware/software allows the use of this hardware to phaselock a frequency comb. More generally, together with the hardware, it provides a digital control box that can support a dual-channel phase-locked loop including the front-end IQ detection of the input rf signals. While this digital control box could therefore be used to phase lock other systems, the discussion below assumes the user is operating a frequency comb.
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+Getting started
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+Read the "Instructions and operation manual for RedPitaya DPLL.pdf" file.
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+Additional information
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+Additional information can be obtained from the instructions manual of the NIST digital control box (https://www.nist.gov/services-resources/software/fpga-based-digital-control-box-phase-stabilization-frequency-comb).  The Red Pitaya digital phase-locked loop is based on this software and thus shares many of the same functionality with some differences.
+Some other information is included in the slides for the CLEO 2017 presentation associated with this project (Slides_CLEO2017_JDD.pptx) and in the Review of Scientific Instruments article on the frequency comb (http://www.nist.gov/manuscript-publication-search.cfm?pub_id=918079), which contains information about the NIST digital control box version of the digital PLL.
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+Disclaimer
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+This is not a commercial product, this is a research tool so there are some “rough edges” and limited documentation, if you need support you can contact me at ([email protected]) – although I cannot guarantee that I will answer quickly all the questions, but I will do my best to do so.
+This software was built starting from two existing code bases: the NIST digital control box software for most of the FPGA firmware and all the Python code, and a part of the Red Pitaya software for the Zynq embedded software and FPGA firmware.  Both the NIST and the Red Pitaya code were released in the public domain with a specific license, both placed in the subfolder "Licenses".
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