industrial//industrial automation//discrete automation

Discrete automation is the branch of industrial automation that controls processes made of countable events, as in automotive, packaging, logistics, assembly and machine building. A part is present, a robot acts, the conveyor advances, the part leaves. Each step is a clearly defined event and the logic is a sequence of conditions. Its counterpart, process automation, reasons in continuous variables held at setpoints: the first is a sequence problem, the second a regulation problem, and the split of tooling between PLC and DCS follows that line.

Discrete automation is the branch of industrial automation that controls processes made of countable events, as in automotive, packaging, logistics, assembly and machine building. A part is present, a robot acts, the conveyor advances, the part leaves. Each step is a clearly defined event and the logic is a sequence of conditions. Its counterpart, process automation, reasons in continuous variables held at setpoints: the first is a sequence problem, the second a regulation problem, and the split of tooling between PLC and DCS follows that line.

PLCs dominate this world: Ladder logic was invented for exactly this kind of interlocked sequence (IEC 61131-3).

The machine is often delivered whole by an OEM with its own controller, sensors, actuators and HMI, and then has to be integrated with the plant. That is where a lot of interoperability trouble is born.

Discrete automation becomes demanding with coordinated axes, servos and robots, which push the timing requirement from milliseconds to synchronized microseconds (motion control).