Ladder Logic

[engr.irfankhan]

hi! every body i need info on ladder logic, why auxiliary switches are used in ladder logic and whats there purpose??

 

[Lancie1]

Engr,

As for me, I try not to use auxiliary switches in ladder logic. I do use START switches, and especially STOP switches. You never want to write a program without a method to STOP the process. I do not consider those "auxiliary" but NECESSARY.

 

[bernie_carlton]

he may be referring to Control Bits. Single bits which are representative of inputs or outputs.

 

[Lancie1]

Bernie, it could be poor translation to English. "Auxiliary Switch" should not mean an internal PLC memory location, whatever its purpose.

 

[TConnolly]

It could also be a switch described as Auxiliary in the address comment.
Maybe the machine has a Main Start/Stop and an Auxiliary Start Stop.

Without more information we really have no idea at this point. If the original poster can attach a rung screen shot or attach the program and give us more details that will be helpful in getting a good answer.