PLC Programming Fundamentals – OSR Instruction

The OSR, also known as One Shot Rising, instruction allows a programmer to create a scenario where an output is energized for a single scan when a transition from a logic low to a logic high is detected on the input side of the instruction. The OSR is identical to the ONS in the performance. However, it does give the programmer slightly more flexibility due to a dedicated output bit. Furthermore, the instruction is also a lot more explicit. It resides on the right side of the ladder logic rung and allows the user to use its output tag where needed within the program.

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