You will need to use an analog input or output card depending on your requirement (you question is too open).
Then you need to know what your devices uses i.e. either 4-20mA or say 0-10V. you need to do necessary hardware settings in the S7 software and on the card itself- there is a jump you will need to set, very simple.
You can then first use a VAT to see if you can get values on your screen from the analog device, check input polority of the device to be sure, correct any mistakes.
Note that the analog card will give an integer value ranging fro zero to a max value of say 27648 or another value which depends on the number of bits your card encodes.
dear zahir salih, i wanna have ur email. i'd like to get in touch in future and i need u in this conenction. can u let me know in detail about analog interfacing? thanks. ur brother.
