If you're question is about the possibility to use analog inputs with a S5 PLC, then the answer is definitely YES. To use an analog input in S5 you need an analog input card for the S5 PLC. This card (usually 4 inputs) converts the analog input signal to an integer number (KF format). The PLC can then process this integer.
BTW this is the common method for using analog signals on all PLCs.
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