Automatas Programables by Josep Balcells is considered a seminal text in the Spanish-speaking engineering world. Its primary value lies in its holistic approach; it does not merely teach coding syntax. Instead, it teaches the entire ecosystem of industrial automation—from the sensor level to the network level. By focusing on the IEC 61131-3 standards, Balcells ensures that the knowledge remains relevant across different hardware platforms, making it an essential resource for anyone entering the field of industrial control.
for PLC learning (in Spanish):