阐述了一种高精度多通道温度控制器的设计方案。通过高速转换输出的16 位AD 芯片AD7705 以及ARM 处理器,可以实现快速轮番采集多路温度信号。采用积分分离的PID 算法,计算并输出PWM 控制信号,通过固态继电器控制加热器件通断时间,使得各通道温度达到预设温度并在控制精度允许范围内小幅度波动。通过Modbus 通信协议与上位机进行通信,可以实现单台上位机同时监控多个温度控制器。

A design of high precision multiple channel temperature controller was introduced. By using 16 bit high speed AD7705 and ARM processor, signal of temperature from multiple channels was collected effective in turn. PWM control signal was calculated and output using integral separated PID algorithm. The on-off time of heater was controlled using solid state relays, which make temperatures of each channel approach the presetting value and fluctuate in allowed range of control accuracy. Simultaneous control of multiple temperature controllers was realized with only one upper computer through Modbus protocol.