TABLE 1.
Summary of the main characteristics of different types of control systems for bioreactors.
| Type | Controller | Monitor | Main characteristic | Drawback | Strength |
| Pre-digital | – Human operation | – Human observation | – Distributed control and distributed administration | – Human error | – Low capital investment |
| – High variability | – Lower maintenance cost | ||||
| – Less automation | |||||
| – Low efficiency | |||||
| HSCSa | – Microcomputers | – Analog/digital detectors | – Distributed control and central administration | – High capital investment and maintenance cost | – High automation |
| – Point-to-point communication of signals | – Complex wiring | – High efficiency | |||
| – Function redundancy | – Complex control strategy | ||||
| – Low interoperability | |||||
| FOCSb | – Computers | – Digital detectors | – Distributed control and central administration | –Communication constraint of fieldbus | – Simplicity, accuracy, low maintenance cost |
| FCSc | – Smart devices | – Smart sensors | – Signals communication via fieldbus | – Signal delay and packet loss | – High interoperability, stability |
| – Complex control strategy | |||||
| NCSd | – Networked computers | – Digital detectors | – Distributed control and central administration | – Communication constraint of network | – High efficiency, low maintenance cost |
| – Smart devices | – Smart sensors | – Signals communication via network | – Signal delay and packet loss | – High interoperability, stability | |
| – Risk of cyber-attack | – Advanced management |
aHierarchical structure control system, including PLC and DCS systems; bFlat organizational control system; cFieldbus control system; dNetwork control system.