Electronic computing machines are diverse, driven by the need to solve specific applications. Among them, it should be distinguished programmable logic controllers (PLCs), distributed control centers (DCSs), and computer numerical control (CNC). The most crucial common criterion of all three systems is that they are used to control and automate production processes. Moreover, each of the systems controls digital processes and programs. In addition, each of the industrial automation areas has grown as a replacement for relay systems.
The main task of a CNC is to determine the trajectory of machine components and assign tasks to actuators based on a flow chart through a mathematical calculation for curves. In contrast, a PLC is an electronic computing device that operates in real-time. A PLC cannot have as much flexibility as a CNC has: this means that the potential for using a CNC is not limited (Hess, 2017). A PLC, on the other hand, is inflexible: one cannot modify the program slightly to suit a particular task; instead, one has to rewrite the PLC code (Unitronics, 2017) entirely. CNCs tend to be more expensive than PLCs, but with more cost comes more reliability and functionality. A PLC is primarily focused on using logic operators, whereas a CNC is geared toward mathematical calculations (Connectivity, 2017). At the same time, the PLC allows users to develop their applications to automate individual tasks. Against this background, the extended functionality of DCSs, which can combine and integrate multiple machines in production, must be emphasized (CS, 2018). Whereas a PLC features a comparably simple operating system focused on scanning discrete inputs and outputs, a DCS requires much longer response times due to the increased number of background processes. Consequently, the profitability of a DCS is calculated from several thousand points, whereas a PLC requires far fewer inputs.
The applications are also different for all three systems. For example, CNC is used on milling, turning, grinding, and laser machines. These are any automated systems that require fine mechanics. PLC interacts better with other systems, so such machines are used for electromechanical tasks, attractions, chemical, and energy industries. On the other hand, DCS is an even more extensive link, and its use is relevant in whole factories and plants where serial production is required. Thus, any chemical, energy, oil, gas, or pharmaceutical production almost certainly uses the DCS.
References
Connectivity. (2017). PLC vs CNC: Is there room for both in the factory of the future? Connectivity For IR.
CS. (2018). What is a distributed control system? CS.
Hess, B. (2017). What is CNC machining? An overview of the CNC machining process. AMN.
Unitronics. (2017). What is the definition of “PLC”? Unitronics.