From the course: PLC Program Flow and Control Instructions

Unlock the full course today

Join today to access over 22,600 courses taught by industry experts or purchase this course individually.

Master control rest (MCR) instruction

Master control rest (MCR) instruction - Ladder Logic Tutorial

From the course: PLC Program Flow and Control Instructions

Start my 1-month free trial

Master control rest (MCR) instruction

“

- [Instructor] The Master Control Reset instruction, or MCR, is an output instruction that works in pairs, and it has no address. It is used to disable or enable a section of rungs within a ladder logic program. One MCR instruction is used to define the start of the ladder area to be effected, and one MCR instruction is used to define the end of the area. And input instruction is usually added on the rung of the first MCR to control rung logic continuity, and to control when to start and stop the MCR effect. The ending MCR instruction must be the only instruction on the rung. The operation of this instruction goes this way. When input instruction is true, making MCR instruction true, all outputs within the MCR zone act normally according to their rung logic, as if the zone does not exist, we call this a true MCR zone. When the MCR instruction is false, all rungs within the zone are treated as false. We call this a…

Contents