10 analog inputs SIMATIC S7-300

Thank You Very much  Chartier

Sorry for late reply...

Your Explanation is very useful for me to develop program

Once again i need to say your are genius in PLC Programming

I keep on touching with you. Your are very important person for me to develop my knowledge in PLC siemens step 7

dchartier

Hello Licary;

Now that  you have generated your hardware confuiguration, you have been given the addresses by which you will be able to read in or write out your analog values (look ak tyour screenshot).

IN addresses are given as 256..271 and 272..275.

OUT addresses are given as 288..303 and 304..307.

These are all peripheral addresses, outside of the (mainly digital) input and output image tables.

Where and when do you need peripheral addressing?

Peripheral addresses need to be designated in your program as PIWxxx, (in this case, they are input word values,16 bits), or PQWxxx for output values.

So with FC105 (SCALE, to read in the voltage/current values from your sensors) you need to use the following addresses: for input channel 1 (PIW 256), for input channel 2 (PIW258), for input channel 3 (PIW260)… and for input channel 10 (PIW274).

And with FC 106 (UNSCALE, to write an analog output to your analog output channels), you need to use for output channel 1 (PQW288), for output channel 2 (PQW290), for output channel 3 (PQW292)… and for output channel 10 (PQW306).

For descriptions of FC 105 (SCALE) and FC 106 (UNSCALE) functions  refer to the following help threads (note that FC105 and FC106 (SCALE and UNSCALE) are located inside the TI-S7 Converting library in your LAD/FBD/STL editor):

escalar entrada analogica en WINCC 

Output voltage on AO module too high

You need to call FC 105 once for each channel, with its correct input address and scaling values. Same for each ouput channel, FC106 must be called once for every output value you want to generate.

One problem newbies often have is for he parameter „Bipolar“: you need to generate an Always_On and Always_Off bit (to set the value to 1 or 0. Look up the information in this thread:

Always On or OFF bit 

Hope this helps,

Daniel Chartier