Ladder Logic

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

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.

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

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

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.