How to choose what production signal to monitor?

An industrial digitisation project is as successful as the preparation that goes into it. The goal of this post is to help you understand what a good production signal is (e.g. product was produced, a product was scrap, production started etc.). And how you can find it in your production process.

By going through this information and knowing what to look for, you will make sure that you get the best results out of your OEE monitoring.

Understanding what production signal to monitor

First, you need to understand what the production signal is that you want to register. Defining the production signal is very much dependant on your production process and what it is that you are producing.

Secondly, by knowing what the signal is that you want to monitor, we need to determine the best location to get it.

Understanding these two things will make it much easier to get an automatic production monitoring system, like Evocon, up and running.

How does Evocon’s OEE monitoring system work?
What is the right production signal for you?
What part of the production process should I monitor?
How do I get production signals from my machines?

How does Evocon’s OEE monitoring system work?

A common misperception is that you need different production signals (machine on, machine off, breakdown, changeover etc.) to implement Evocon in your factory.

In actuality, it is much more straightforward than it looks. All you need to monitor your OEE, machine downtime and other KPI-s is one good production signal from your line or machine. In most cases, this is a signal that indicates that something was produced.

By having a correct input from your production equipment and knowing some basics about your production process, we can easily automate and digitise most of your production data collection.

What is the right production signal for you?

Depending on your production process, a right signal can be an event that marks product produced, length produced, a certain amount of minutes a machine is working or something else.

To generalize, a right signal is one that changes form from 1 to 0 (or from 0 to 1) and this is the event that we want to track. For example:

  • A soda bottle moves away from the sensor (event), and the signal (via a sensor) changes from 1 to 0. This indicates that the soda bottle completed one step of the production process (product is ready) and needs counting (measurement).
  • A CNC machine completes one cycle, and the Andon light (corresponding PLC output) changes from 1 to 0. Depending on what data you want to collect, we can interpret the cycle in different ways:
    • One cycle corresponds to one or multiple products (counting pieces).
    • One cycle corresponds to the number of minutes the machine is working (time mode).

In general, Evocon is very flexible in what it can monitor. Quite often it takes no more than one picture or video of your production process, and we can already suggest what the best signal for you is.

What part of the production process should I monitor?

Once you know what it is that you want to monitor, then finding the right location from where to take the production signal, becomes easy. Just observe your production line or machines and notice where the event occurs that needs monitoring.

Here are a few examples of how to find a suitable location:

  • If there are no existing sensors on your production line, then find the area where the event that interests you is. For example, bottles filled or capped, boxes packed, logs cut etc. You can then mount a new sensor at that location.
  • Provided there is an existing industrial sensor or a moving part (knife, clip) that corresponds to the cycle that you want to measure, then you have found the right place.
  • If you find a moving part or a sensor, then you should look where the wires lead as it might be possible to take the signal from an electrical circuit.
  • If you have circuit diagrams at hand and they are readable. Then you can start with the technician finding a potentially fitting signal from the circuit diagram. And after that from the machine. Be sure to observe and decide whether the signal is suitable or not.
  • If a suitable signal records two or more signals per one product, then we can filter the excessive ones.

How do I get production signals from my machines?

There are different ways that you can get production signals from your machines. The method to use mainly depends on what production process you have. In most cases it comes down to four choices:

  • An existing industrial sensor or a new one.
  • Connection with machine PLC.
  • Connection with Andon light.
  • HTTPS requests (hardware-free solution).

To understand all these options in more detail, please read “How to get production signals from machines?” and find out what the best method for you is.

If you have any questions, then don’t hesitate to contact us and we will help you figure everything out.