1. Capture Sensor Data

The first step in the monitoring process is capturing critical tool performance data or machine data, using sensors. There are many types of sensors, including force, optical, acoustic, motor load, etc. Each application may require the use of different sensors, or multiple installations of one sensor type.

Whichever type of sensor is used, the sensor is located to best observe the machine process. As the machine runs, it converts mechanical energy into electrical signals and sends them to the process monitor.

2. Process and Filter Data

The monitor receives the data about the process from the sensors, and processes it. Before it can analyze the data, it may need to amplify the signal or filter it. It may apply a low-pass or high-pass filter, or use various signal-processing routines like smoothing or clipping, all depending on the application and the signal present.

3. Analyze Data

After the signal has been conditioned, it can be analyzed. The monitor measures and "learns" the parameters of several "good" cycles. It may measure the peak reading or the area under the curve, or it may calculate an envelope that all cycles must fall within. It may even look for some other special characteristics, like y at x or the median value. When the monitor has learned these parameters, it will store them for referece.

4. Continue to Monitor Machine

Once the monitor has learned the process, it will continue to observe it. For each sensor signal that is processed, the monitor compares the signal from the sensor to the stored parameters. If they match, the signal is consistent and it passes the test.

If the signal profile falls outside of the acceptable parameters and does not match, something has gone wrong in the process. Perhaps a tool broke, a part was missing, or there was a problem with the machine. Whatever the cause, the monitor will display an error message, warn the operator, and stop the machine to prevent further damage.

5. Feedback and Data Storage

If a sensor signal from the machine cycle has passed or failed, the monitor will alert the operator via warning lights, LED's, or the color of its screen. If there is a failure, the monitor will also display what went wrong, when, and how and where. This data can also be stored for later downloading and analysis.

Process Monitors also have relay outputs that can be programmed to control the stop cycle of the machine or other equipment. For example, the relays can "top-stop" a machine or "cycle-stop" a conveyor, as well as control a sorting gates to divert a bad part from the line before it causes more damage, or contaminates a production lot.