Lmlmm

Assume,.for.example,.that.the.encoder.generates.600.pulses. per.revolution,.and.it.takes.000.motor.revolutions.to.move. the.platform.from.one.position.to.another,.moving.the.platform. from.position..to.position.6.(5.positions).takes.5000.motor. revolutions.or.30,000.encoder.pulses..In.most.practical. applications,.the.frequency.of.these.pulses.is.too.high.for.them. to.be.counted.with.inputs.that.are.not.associated.with.a.highspeed.counter.. Interrupts. S7-200.PLCs.incorporate.instructions.for.use.with.interrupts.. Interrupts.are.used.to.initiate.a.specific,.short.PLC.program. segment,.called.an.interrupt.routine,.when.an.internal.or. external.event.occurs..After.the.interrupt.routine.has.been. executed,.control.is.returned.to.the.main.program. Three.types.of.interrupts.are.supported.by.S7-200.PLCs,. communication port interrupts,.I/O interrupts,.and.timebased interrupts..Communication.port.interrupts.are.used. to.control.a.communication.port.operated.in.Freeport.mode.. I/O.interrupts.are.used.to.respond.quickly.to.high-speed.I/O. transitions,.such.as.those.associated.with.high-speed.counters. or.pulse.train.outputs..Time-based.interrupts.allow.the.user. program.to.execute.an.interrupt.routine.on.a.cyclic.basis. Each.of.these.types.of.interrupts.has.an.associated.priority. that.determines.which.interrupt.is.processed.first.in.the.event. that.two.or.more.interrupts.are.requested.at.the.same.time.. Communication.port.interrupts.have.the.highest.priority.and. time-based.interrupts.have.the.lowest.priority. Pulse Training Output (PTO). S7-200.PLCs.have.two.PTO/PWM generators.that.create.either. a.high-speed.pulse.train.or.a.pulse.width.modulated.waveform.. One.generator.is.assigned.to.output.point.Q0.0.and.the.other.to. output.point.Q0...When.a.generator.is.activated,.it.controls.its. respective.output. Pulse Train Output (PTO).is.used.to.provide.a.series.of.pulses. to.an.output.device,.such.as.a.stepper.motor.driver..The.PTO.