Custom 20-bit real time networked power supply controller

The design of the new Taiwan Photon Source, a high-brightness, low-emittance synchrotron light source, calls for very high precision control of the beam. This in turn requires very high precision power supplies. The power supplies are designed and manufactured locally in Taiwan by ITRI, while the power supply controller is a custom design from D-TACQ.

The controller features 20-bit analog outputs, and 24 bit analog readbacks. With analog out looped back to analog in, the system achieves a noise level of 4 microvolts RMS. Realtime control data streams into the unit on fiber optic multi gigabit links; an embedded computer running an EPICS process controller for supervisory functions and data monitoring. More than 400 process variables are presented on Gigabit Ethernet for external use.

D-TACQ leveraged work from existing standard designs and the minimum of new custom design to produce a composite module that fits in the control slot of the existing psu crate, while minimising design costs.

To achieve a precise and stable output, extreme attention is paid to thermal stability as well as normal signal routing and filtering rules. The unit includes high precision thermal monitoring to allow compensation for thermal drift.
Local FPGA logic includes a summing junction to combine setpoint data from 4 possible sources (2 real time data streams on fiber-optic, a local AWG function and slow settings specified on Ethernet via EPICS). A comprehensive set of CSS/BOY remote GUI screens provide a complete operator interface.

D-TACQ manufactures a range of off the shelf high performance data acquisition hardware and systems. The systems are highly programmable and can be adapted to meet many requirements, but where this is not enough of course we can advise on custom systems for an exact fit.