semilogical
Member
In my world a normally open contact in a PLC is called an XIO. A normally closed contact is called an XIC.
Now, if you use a normally closed contact on a push button you would normally use a normally open (XIC) in the program to make your system work.
i.e.
xic motor_stop bst xic motor_start_ nxb xic motor_aux bnd ote motor_coil
or in this case:
NO Start NC Stop Output
it would be bst xic NO_Start nxb xic Output bnd xic NC_Stop ote Output
Here you are using the coil for the seal, in most cases you would use an auxiliary contact (especially in the motor start arena) to prove your output has actually turned on the motor coil.
BTW, I suck at trying to format keystrokes here to make it look like ladder logic. If I could insert a picture I'd show you that way.
Now, if you use a normally closed contact on a push button you would normally use a normally open (XIC) in the program to make your system work.
i.e.
xic motor_stop bst xic motor_start_ nxb xic motor_aux bnd ote motor_coil
or in this case:
NO Start NC Stop Output
]---+---| |-------+--------| |----------------( )
| |
| Output |
+---| |-------+
it would be bst xic NO_Start nxb xic Output bnd xic NC_Stop ote Output
Here you are using the coil for the seal, in most cases you would use an auxiliary contact (especially in the motor start arena) to prove your output has actually turned on the motor coil.
BTW, I suck at trying to format keystrokes here to make it look like ladder logic. If I could insert a picture I'd show you that way.
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