First of all i would to thank everyone who keep on giving their knowledge or advise to those people who need an advise or need to be tutor(like me?) obviously!. THANK YOU! OK. I'm a new beginner in PLC..I'm using OMRON CJ1M-CPU11 plc...my problen is....i want to create a program that will send an error if wrong sequence input has been made. Here it goes... Good Sequence : input(0.00,0.01,0.02,0.03,0.04) and then Buzzer (e.g: 1.00) If Sequence input begin with 0.01 or 0.02 and so on ... buzzer will activate for ERROR! please help...i'm trying to use Logic instruction but it doenst work i got RED line in CX PRogrammer...