The MAX22191 is designed to only operate with a positive input as in IEC 61131-2
In some applications it is desireable for the part to operate with bipolar inputs. This can be accomplished by adding a diode bridge to the input. Note that, when using the diode bridge, we actually we need to add two diode drops.
At the MAX22191 output use an optocoupler with an LED that requires 2.0mA or less.