Difference between an [XIC] and an [OSR] instruction


#1

An [XIC] (examine if closed) instruction is used in a ladder logic program to determine if a bit is on (1). When the instruction is executed, if the bit addressed is on (1), then the instruction is evaluated as TRUE. When the instruction is executed, if the bit addressed is off (0), then the instruction is evaluated as FALSE.

The [OSR] (one shot rising) instruction is true for one PLC scan when the rung conditions preceding the OSR go from false-to-true.