Fiber Bragg grating (FBG) sensors have been widely used in monitoring of the mechanic equipment. However, for measuring high-speed dynamic signal of a large mechanical equipment, the demodulation rate of the interrogator should be very high, while the number of sensors could be tens or hundreds, thus, a large amount of sensing data could be generated. Nonetheless, a network throughput of the interrogator based on the software stack is relatively low and a large amount of data cannot be transmitted simultaneously, which becomes the bottleneck of the sensing system. In order to promote the network throughput, a hardware TCP/IP stack based on the field programmable gate array (FPGA) is proposed. In contrast to the existing hardware stacks, this stack is designed with a new module structure that is divided according to functions instead of protocol types. It can realize both UDP and TCP transmissions with less logic elements than similar designs. Unlike ASIC TCP/IP stack, the entire system can be realized on a single FPGA chip and upgraded without changing of the original hardware circuit. The proposed design has two key features. Firstly, the hardware stack can be connected directly to the data acquisition logic part without software operations thus the data throughput from the signal acquisition to the network transmission can maintain a relatively high speed. Therefore, the system can demodulate data from hundreds of sensors at high speed and transmit them in real time. Secondly, the module structure is clear and independent of specific FPGA platform. Consequently, it can be transplanted or upgraded easily in order to meet different practical demands. The proposed design embodies the characteristics and advantages of the system on a programmable chip (SOPC). In order to validate the proposed design, all logic modules were simulated and the design was tested on the circuit board. Performance test results have shown that UDP and TCP throughputs of the proposed hardware stack are up to 80Mbps in the case of 100Mbps Ethernet controller chip, which is about eight times higher than throughput of software design. Finally the design was verified by monitoring of the oil pipeline platform. The obtained results have shown that proposed design can detect the vibration frequencies of the oil pipeline that are around 600Hz and it can sample 288 FBG sensors and transmit sensor data correctly. Thus the proposed design is suitable for a large sensing system intended for the dynamic monitoring of the mechanical equipment.

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