FX1S Use a frequency signal as start and stop

[Pvuorio 0]

Hello Anybody have a good idea of how to use a frequency signal as start and stop in FX1S plc? I would need to start the process when a rotary device is running and only signal available is the 0-510 Hz from the tacho generator on it. Patrick

[Crossbow 296]

Use the high speed counter functions to being in a pulse signal from the tach, count it over a defined time period, do the math to determine speed, and then do a 32-bit compare to see when you are in range. I don't recall if the FX1S (which is the really low end model) had a speed measurement command or not.

[bobtalbot 1]

I believe the FX1S supports the SPD instruction this might be useful using Crossbow's suggestion of comparison

[JRoss 84]

Use the SPD command to detect the speed of the incoming pulse-train. It is available on the FX1S.

[Pvuorio 0]

Hello Thanks for the inputs. However i haven't fully understand how to be able to use the functions to do what i am looking for. As my project is to start a lubrication pump for a engine when it is running. So i'm interested in just to detect that the pulse train is there and then run the pump. The pulse train is a frequency from a tacho generator with a frequency from 0 to maximum 510 Hz. Patrick

[panic mode 246]

1. just configure plc and make sure to use high speed counter 2. wire sensor to plc input which is associated with the high speed counter 3. use SPD instruction to measure speed (frequency of pulses) 4. perform comparison as usual ( something like "LD> D0 D100" or similar....)