Data Acquisition System for Fibre Bragg Grating Sensors
A data acquisition (DAQ) system collects, stores and distributes measurement data. DAQ systems are used in industrial, commercial, environmental and scientific equipment to capture electrical signals or environmental conditions on a computer. This article describes a DAQ controller designed by Argus Technologies for interrogating Fibre Bragg Grating (FBG) sensors.
Overview
The most straightforward way to interrogate an FBG sensor is to illuminate it with a broadband light source and send the narrow band reflected by the FBG to a wavelength detection system. In this design the reflected light falls on a linear CCD image sensor, and an Argus-developed FPGA controller board reads it. The system supports eight sensor channels.
Hardware
- Agiltron 1x8 latching fibre-optic switch (MEMS)
- Hamamatsu InGaAs linear image sensor
- Analog Devices AD9826 image signal processor (ADC)
- Xilinx Spartan-3A DSP FPGA (XC3SD1800A-4CSG484C)
- Cypress PSoC 5LP programmable system-on-chip (CY8C58LP)
- SRAM for data storage
- 25 MHz system clock; single 9 V supply (about 300 mA)
Block diagram of the DAQ controller
How it works
- The FPGA receives command bytes from the PC over UART and acts on them.
- It controls all other peripherals on the FPGA controller board.
- It receives the sensor signals and generates the control signals for the ADC.
- It combines the ADC's 8-bit outputs into 16-bit words and stores them in memory.
- It sends the 256 x 16-bit words (one per pixel) to the PSoC 5LP.
- The PSoC passes the data to the PC or another host over USB, where it is displayed using LabVIEW.
Key features
- Detects narrow-band signals from a broadband infrared/near-visible source
- UART, USB and flash interfaces
- Fully synchronous design written in Verilog HDL
- Silicon-proven on the Spartan-3A DSP FPGA; portable, accurate and easy to integrate
2026 note
The same architecture can be moved to current FPGA families and microcontrollers, with Ethernet or USB 3 for faster data transfer and Python or web-based software in place of LabVIEW. Argus can adapt the design to new requirements.
Argus Technologies offers customised product design on a turnkey basis or with limited involvement in your project: product design, FPGA design, embedded software, PCB layout and contract manufacturing from prototype to production. Contact us.
