transferring program from medoc

[bigjoe 0]

Hi just learning plc and I made this simple program from medoc: x0 x1 --l l---l/l---------------(m0) m0 l --l l-l m0 --l l---------------------(yo) after doing so I save it and transfered it to the plc, after transfering, I started doing the wiring and after that I push ON the button for X0 and there is no output at all. I check the wiring it all seems correct. Did I miss something? johnny

[bigjoe 0]

the wiring on the input goes like this: PLC Input: com-----PB(NO)------X0 com-----PB(NC)------X1 and on the output goes like this: PLC Output: +V-------RELAY----(com0-Y0)--------V- com0 and Y0 terminals acts like a NO swicth. regards, johnny

[navillusi 2]

The mistake I believe you are making is that your X1 is a normally closed switch (I assume a stop button) the device in the program is a negated contact. Thus it will be true when the input is 0 (switch pressed) From the looks of it, if you hold the stop button in and press the start then it will work? Change the ]\[ to a ] [ for the X1 Do not confise a negated contact in the PLC with a normally closed contact in the outside world, they are different!

[rajsiyer 7]

Yo Johnny..... Yo doin alright man. Jes change the XIO(symbol for NC) at X1 address to XIC and work your baby will. Have fun. Old Raj always happy to help

[Sergei Troizky 26]

Ensure that: - The PLC Run light is On. - No Error light On or blinking. Connect the S/S input to + (that is configure inputs for sinking signal). Connect COM0 to -.

[bigjoe 0]

Hi thanks guys for the replies! I knew it that my mistake was the NC contact that I wired on X1, it's because there is an initial signal coming from it tha reverses the logic on the ladder right? Thanks, johnny

[Crossbow 295]

Don't think of -][- and -]/[- as normally open and normally closed. The best way I can explain it for beginners is -][- is looking for the input to be ON (true) and -]/[- is looking for the input to NOT be on. I explain it as a NOT contact in my classes and everyone gets it. -]/[- actually passes power when the input it's addressed to is OFF.