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General => Technical support => Topic started by: EtienneP on September 23, 2019, 12:10:15 PM

Title: Max frequencies on regulare input
Post by: EtienneP on September 23, 2019, 12:10:15 PM
Hi,   I need to Count 8 prox at 12VDC  operate between 30 to 50hz. I wan't to know if I can use the Input 7-15 of an FMD1616 supply at 12VDC to read this! The high speed input was already use for an encoder.

Regards!

Etienne
Title: Re: Max frequencies on regulare input
Post by: support on September 26, 2019, 11:29:10 PM
The FMD1616 PLC has an I/O scan time of 2ms. The program scan time depends on how your program is written and can vary.

If you only run a couple of rungs of ladder program and it does nothing more than just count pulses it may be able to handle up to 200 Hz. But if you have custom function that may take up long time (e.g. communicating with 3rd party devices via serial or Ethernet port) then the time varies. It is best if you use a separate FMD88-10 which has 4 interrupt inputs and 4 regular inputs and if this slave PLC does simple counting you should be able to handle your 30 to 50Hz pulse inputs.