How can the CPU analog inputs of the SIMATIC S7-1200 also measure currents of 0-20mA

s7-1200_cpu_analoginputs_current_01

Fig. 01: Connection of a sensor to a voltage source as a 2-conductor connection

s7-1200_cpu_analoginputs_current_02

Fig. 02: Connection of a sensor to a voltage source as a 3-conductor connection

s7-1200_cpu_analoginputs_current_03

Fig. 03: Connection of a sensor to a voltage source as a 4-conductor connection

s7-1200_cpu_analoginputs_current_04

Fig. 04: Connection of a measuring transducer with voltage output to a current source as a 4-conductor connection

References :
https://support.industry.siemens.com/cs/document/67396370/how-can-the-cpu-analog-inputs-of-the-simatic-s7-1200-also-measure-currents-of-0-20ma?dti=0&lc=en-WW