counter circuit

Hi there,

I need your help to give me some light in this ladder diagram i have attached, extracted from a working program using idec FA-1 PLC. It's a counting circuit that i could not figure out how it is working. all counting circuit are in the same sort of arrangement. The middle rung has a coil with no label at all as it appeared on the actual program. I would appreciate any info...

Cheers.

Wow, talk about a blast from the past. I haven't seen one of those for a very long time, probably close to two decades, but believe it or not I think I still have a hand held programmer kicking around in one of my boxes somewhere.

Your ladder drawing is a little off.

                    +------------+

                    |            |

---] [--------------+RESET       |

   M07              |            |

                    |            |

--] [---] [---]/[---+COUNT UP    |

  I01   I03   I04   |            |

                    +------------+



---] [---------------------( )---

   C1                      M07

Once the counter reaches it preset it resets on the next scan. C1 and M07 are on for just one full lap of the scan.

thanks mate for the reply, what you posted is exactly how that circuit works. I might ask again one time, we are dealing with dinosaur equipments at the moment...

many thanks...