Thanks for the hard work you did getting Basic52 to fit into a newer IC. I would think this beats the stuffing out of the PLC argument.

Outside industrial applications, it certainly would if the BASIC also built the hardware.

facts about BASIC ('51) vs ladder (PLC)

In industrial you have tons of people capable of modifying ladder, very few capable of BASIC. Thus for industrial products ladder is more or less mandatory. In other environments, there is no likelyhood of anyone capable of either, thus BASIC or ladder makes no difference.

Now, for ladder there is ready made hardware (PLCs) proven in industrial environments, of the many '51 "ready made" boards, I recall none with industrial noise protection, not to mention that I recall none in a nice steel case. a PLC, however is proven to withstand industrial noise and comes in a nice case. Another issue is that all PLCs I know of (can) come with relay contact outputs, I know of no such "ready made" '51 board.

So, in conclusion, if you are to make a sufficient number of units you may see an advantage by custom designing a '51 system, if the unit count is low, buying a proven reliable industrial PLC is by far a better bet.

Erik