Many 4-20mA analog sensors only has two wires connection and are designed to be powered by the 4-20mA output current that flow through it. These type of sensors can be interfaced easily to the 0-5V analog inputs of the PLC as shown in the following diagram:
The sensor output will be converted to a 1-5V analog voltage and can be read by the PLC using the ADC(n) statement which will return readings of between 820 and 4092.
If the ADC is of 0-1V type (such as ADC1 & 2 on T100MD1616+) then just change the resistor to 50 ohm.