Top 5 PLC programming languages
Before we go through the 5 PLC languages, let’s briefly mention what a PLC is. Remember Stuxnet? The exploit took advantage of the grand daddy of IoT devices, PLCs.
Programmable Logic Controllers(PLC) were designed to replace electromechanical relays. Back in the day, you had to get an electrician to risk life and limb to rewire the relays if you wanted to make an adjustment to a line. With the advent of PLCs, electricians were taught how to use programmable logic to make updates.
Programs that allow for such updates are often written on a PC, and then transferred via cable or USB to the PLC itself. These programs are stored in non-volatile memory to ensure that the processes they are designed to control continue to run smoothly. You don’t want the program that controls prison doors in high security prisons to suddenly be wiped out.
Like any other machine that can execute programs, there are a bevy of languages available to break down into machine code. The languages below have their use cases. Some are great for their simplicity within the context of electromechanics while others are great because of their complexity.
There are only 5 languages that are considered to be standard languages for use on PLCs, according to IEC section 61131–3. Here they are:
