Arthur97
So,the pdf is a a circuit of a 3 phase motor.F3 is a thermal ,When we push the START button the circuit goes to the K3M relay ,so we have a delta link.K1T is a TIMER ,when the preset time end,K1T  coil closes and the we have Y link through K2M relay.So i have made the ladder in the plc program but it doesnt work.What should I do?
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thiagoralves
Contact "STOP" in POU "program0" must be connected. This means exactly what it reads. Your contact STOP is not connected to anything. Drag your STOP contact around and you will see that it is missing connections. Fix the wiring and you should be good to go
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Arthur97
OK,so i made some changes in my program as it is shown below.I want to define the unit of TON (for example 120 sec) but i dont know how .So the program doesnt run
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thiagoralves
Right click -> Add Variable -> under Expression write
T#120s

Connect your new variable block to the PT pin on your timer. Done.
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thiagoralves
By the way, your timer is doing absolutely nothing on your program, I hope you know. The Q output is not connected to anything, so it won't take any effect in triggering things. Perhaps you need to study a little bit more on IEC 61131-3 programming. Beckhoff manual is a good reference: https://infosys.beckhoff.com/english.php?content=../content/1033/tcplclib_tc2_standard/9007199329147531.html&id=
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