Using Codesys to streamline automation engineering
25 November 2024 
It can take weeks to produce a PLC program from scratch for complex processes with many I/O points and HMIs. Carl Eely, an industrial automation product manager at ABB, explains how the use of open protocols can speed up the process significantly.
A PLC is – in theory, at least – a relatively simple device. It turns things on (1) and off (0). Of course, in practice, a PLC can also do much more than that, which is why programming one for complex industrial automation systems and processes can be labour-intensive and time-consuming.
The complexity levels ramp up even further when you start adding different communications protocols into the mix. This presents additional challenges, chiefly because not all devices from all manufacturers will always play nicely together. A PLC from one vendor may not communicate easily with a drive, HMI, electrification product, or even a robot, from another. Additional licenses for other protocols – for example, IEC 61850, KNX, BACnet, EtherCat or Profinet – can be purchased, but these are often expensive and may require extra hardware, as well as additional time and programming knowledge to implement.
Learning to program in a new language takes time, and so it’s understandable that integrators often prefer to stick with what they know. The problem is that this effectively locks you into a single vendor, forcing you to either spend additional money on licenses, or change your PLC to match whatever other devices you’re using around it. Alternatively, you can attempt to master a new programming language, but this will typically take even the most capable and fast-learning engineer several weeks at a minimum – which is time you typically won’t have.
Codesys PLCs can provide an answer here. The Codesys programming platform supports all five major PLC programming languages as defined by IEC 61131-3 (LD, IL, FBD, ST and SFC). In practice, this means that a Codesys PLC can be configured to communicate with other devices using multiple protocols – for example, CANopen, J1939 or Modbus – without having to purchase additional licenses. Additional hardware can also open up Extra Ethernet, Profibus, Profinet, EtherCat and CanOpen 2A/2B, while additional software licenses add capabilities for IEC 61850, KNX, BACnet, EtherCat and Ethernet/IP. This compatibility means that one code can be ported easily across to other Codesys PLCs without having to rewrite it entirely, saving vast amounts of training, programming and debugging time.
ABB is one of several manufacturers that offer Codesys-based PLCs, in the form of its AC500 controller.
