Design and Implementation of PT100 Thermal Resistance Temperature Signal Isolation Transmitter Based on FPGA

In the field of industrial measurement and control, platinum resistance temperature signals are widely transmitted in the form of current signals. Platinum resistance temperature signals often need to participate in a variety of control or display process loops after being converted into current signals. The PT100 thermal resistance temperature signal isolation transmitter is mainly used for isolation and transmission of PT100 sensor signal. However, the transmitter has conversion errors and the conversion errors of different channels of the transmitter are generally different, so the current values of different output channels of the transmitter are generally inconsistent. With the long-term operation of the industrial process control system, this numerical difference may increase gradually be unbearable. To solve this problem, this paper proposes a design scheme of the isolation transmitter based on Field Programmable Gate Array(FPGA). In this design scheme, FPGA collects the current value of each output channel, runs the automation correction algorithm, adjusts the value of the output current dynamically, and finally makes the current value of each output channel remain consistent. The hardware implement and test of the current isolation transmitter are carried out and the test results show that this thermal resistance temperature signal transmitter implementation scheme is feasible.