Siemens S300 CPU314C-2PN-DP FREQUENCY

[BenJones]

Hello All, This is my first post in the Siemens part of this web forum. I have used a Mitsu FX PLC before but new with the Siemens S7-300. I am using a CPU314C-2PN-DP which has 4 integrated/onboard high speed inputs (channels 0,1,2&3). I am using these to read in a frequency from a water flow meter where 2-20 L/min corresponds to 20-225 hz. I'm struggling a little with getting them to work. I have found the S7-300 CPU 31xC: Technological functions manual and also an example program. I've also found the FB here : https://support.automation.siemens.com/WW/llisapi.dll?func=cslib.csinfo?=en&objid=18475558&caller=view I have also found the sample example here : https://support.automation.siemens.com/WW/llisapi.dll?func=cslib.csinfo&objid=9837059&nodeid0=33519671&load=content&subtype=133100&switchLang;9837059;2.x=34&switchLang;9837059;2.y=4?=en&siteid=cseus&aktprim=0&objaction=csview&extranet=standard&viewreg=WW I have attached the example to this post that I'm particularly interested in. I am using TIA portal V11 and V12. I have tried to migrate it from V5.4 to TIA V11 or V12 but I get an error message. Could someone please try and migrate it for me? Also, if anyone has used this FB before could they help explain how I wire the flow meter as I'm a little confused. It mentions in the manual but I'm still not sure. The direction is only one way and I'm just reading in a sqaure wave (0-24VDC) Many thanks in advance for any help, Ben Cnt_en.zip