无源开关 meaning in Chinese

passive switch

Heating cooling derivation time : 03600s control period : 1120 s
无源开关量常开：报警时闭合
So can completely satisfy measurement request of various natural gas from all parts of oil and gas field and transmission pipeline in our country . there are switch function of multi - kind signal input , only need to simple setup by instruments menu , namely can realize lightly switching between multi - kind input signal , and has jumproved universality and reliability of instrument
Do为无源开关量信号，操作器在手动控制时输出开关量闭合信号给前级的dcs系统或调节器， dcs系统或调节器收到do状态信号后即停止pid运算，并使操作信号输出跟踪阀位反馈信号。