Wang, in a simple equation with LT and GE you won't be able to realize a controller with a hysteresis (at least it seems that's what you want) - if possible at all I guess you would additionally need Type93 to get the value of OF from the previous timestep. Why don't you use a controller with hysteresis such as Type2d? Best regards, Angela Am 02.11.2011 14:03, schrieb 王洋:
Dear all, Please tell me how to set an equation: OF=1, when CO2%>1000 OF = 0, when CO2%< 700 I tried to use LT and GE, but e.g. it only realize OF = 1, when CO2%>1000 and OF = 0, when CO2% < 1000. I need OF=1, when CO2%>1000 OF = 0, when CO2%< 700 Thanks in advance! wang