How to Track and Monitor Machine Working Time?

time clock 3 min read • February 18, 2020 monitoring oee with plc andon light and button
erki viidalepp evocon

Erki Viidalepp

Head Engineer

With some production machines, it makes more sense to monitor machine working time instead of tracking pieces or any other unit. In other words, we register how many minutes per shift the machine was producing, instead of counting how much was produced. If this applies to your production process, then this article covers everything you need to know on how to do this with Evocon.

What Hardware Do You Need to Monitor Machine Working Time?

When you want to monitor machine working time, you need hardware that sends a signal when the machine is working and stops sending it when the machine stops. Here are the types of outputs or devices capable of this task:

Whatever hardware you choose, it creates signals that are registered by the Evocon’s IIoT device. The device sends these signals to our server. Evocon system processes data and displays it. All of this happens instantly and you see the data displayed in real-time.

Andon light

Andon lights, also called stack lights, are mounted on machines and glow green or red (and sometimes other colours) to indicate the status of the machine. The Evocon device, connected to an Andon light, registers changes in it and uses this information to monitor machine working time.

evocon monitors machine working time using andon light to calculate oee

Status light

Using a status light works exactly the same way as using an Andon light.

PLC

PLC is a small computer connected to your equipment directly. Whereas, newer automated machines usually have PLCs built into them. If there is a PLC signal available that corresponds to a product made, it is best to choose this method over a sensor.

One advantage of that is that any problems with a PLC would be spotted and fixed sooner than if something happens to the machine or a sensor. Also, PLC outputs are generally more stable than sensor outputs.

evocon oee monitoring by connecting to machine plc

The picture above illustrates how Evocon uses a PLC installed in an electric cabinet.

Push-button

To monitor machine working time, you could also use a push-button. Operators would push it in at the start of the cycle and released at the end. However, this is not a very common method. It makes sense in situations when products take more time to complete, are fairly complex, large, or custom. Therefore, we discuss the usage of buttons in our article about other types of production.

evocon oee monitoring with manual work

Which Hardware Is Provided by Evocon?

We provide the Evocon’s IIoT device, together with the power supply. You need to have sensors (or other hardware mentioned above) and cables. If requested, we can supply the sensors and necessary connectors and cables at an additional cost.

Below is a picture illustrating the Evocon setup, including connection to the network and display devices. For more information, please read our article about setting up Evocon.

how to set up Evocon's production monitoring and OEE system

Using Machine Working Time as a Control Signal to Increase the Reliability of Data

Machine working time can be useful as a secondary signal, to “verify” the validity of the primary signal. For example, you may want to make sure that accidental signals, triggered by the sensor during maintenance or cleaning process, do not influence your OEE data.

This is how it would work:

using control signals to increase reliability of oee tracking

using control signals to increase reliability of oee tracking

Here you can see that the primary signal comes from the sensor and the secondary signal – from the Andon light. When the Andon light is on, the Evocon device registers sensor signals as usual. When the Andon light is off, it ignores all signals from the sensor.