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Manufacturing parameters are actual values retrieved from specific devices (e.g. machine controllers) during the production process. The actual values of manufacturing parameters are based on manually set target values and usually affected by numerous variables in the real‐world environment.

For example, two commonly measured parameters that affect the injection molding process are the actual pressure value and temperature value. The manufacturing parameters are periodically updated under the supported refreshing rate of the machine controller.

Nowadays, with many easy‐to‐use Ethernet‐based communication standards for industrial environments, such as Ethernet for Control Automation Technology (EtherCAT), MTConnect, and Open Platform Communication Unified Architecture (OPC‐UA), accessing and retrieving dynamic manufacturing parameters seem not as difficult compared to installing external sensors. This advantage enables manufacturing parameters to be widely applied to record stable data that is not likely to change, so that lower sampling rate can suffice the demand (e.g. temperature, tool number, feed rate, etc).

However, high‐frequency data are not available via applying communication standards. The machine controller is designed to continuously guarantee the machining quality of all time and it executes the machining processes with a high computational complexity. Since frequent requests for accessing parameters have a high risk to interrupt normal operations, the sampling rate is usually set to be within 300–500 μs for each cycle. Once the machine controller overloads, returned values of process parameters might be just default values rather than actual values. Thus, the mainstream methods of machining condition monitoring usually adopt the combination of both sensor signals and process parameters. More details of communication standards can be found in Chapter 3.