Smart relays have further in common with programmable logic controllers (PLCs) than conventional relays. Yet, the term 'smart relay' is used to differentiate them and emphasize the lower price compared with even the smallest of traditional PLCs. People are processed either appropriating pushbuttons and a small screen on the front panel or via a computer. Smart relays were first started over a decade ago; very soon, there were numerous different models available from suppliers of automation products, and it quickly became apparent that some were rebranded versions of others.