SQRT:开根号指令
https://infosys.beckhoff.com/content/1033/tc3_plc_intro/2529101195.html?id=4824318651882052576
EXPT:高次幂运算
https://infosys.beckhoff.com/content/1033/tc3_plc_intro/2529122699.html?id=151299285173388564