There are many reasons why you might need to count items going down a production line, but the most basic would be so you know instantly how many products you’ve made and packed. If a packing box holds say 20 products you might want to have a machine that gives you a new box when the count reaches 20. You could then count how many packed boxes go along a conveyor to be stacked on to pallets ready to ship.

How can I count boxes and products on my production line?

To start you’ll need a sensor. The type of sensor will depend on the type of product you wish to count. If you were counting metal cans you could use a proximity sensor that uses the magnetic property of the can material. For non-metal items, like our box example, you could use a photoelectric sensor. This device sends a beam of infra-red light to either a receiver or reflector.

When the box moves in front of the sensor it breaks the beam and changes the output of the device from 1 to 0 (or vice versa depending on whether you have a PNP or NPN sensor – see our FAQ about PNP/NPN). This is a type of digital output, a discreet binary state, the box is either there or its not, the value is either 1 or 0.

So how do you make 1’s and 0’s useful?

This digital output needs a digital input device to read it. You could use any of our ED range that has a digital input
e.g. ED-588 or ED-516 there is a full list on the ED homepage. Let use the ED-516 as an example it has 16 digital inputs, perfect for connecting to lots of sensors.

There are two wires coming out of the sensor, you’ll need to connect one to the ground on the ED-516 terminal block. The block is numbered so you can’t go wrong. The other wire will need to go into the first digital input e.g. DIn0.

The ED-516 will need to be connected to a power source, you can connect to anything from 5 to 30 Volts. This means you can power the device by directly wiring it into the factory floor, by a PW-600 power adaptor and plug socket or with a PW-650 USB cable from a laptop.

The last step is to plug in an Ethernet cable and you’ll be able to instantly open a webpage with all the ED-516 settings and status.

The instant access webpage will be able to show you the status of the sensor – if there is a box there or not. You can request a count by going to the console and using simple ASCII commands. For example #AAN will request the count, so type #010 and you get a value returned for input DIn0.

However your factory manager isn’t likely to be as familiar with ASCII as an engineer. If you need to get the data in to a more user friendly package so it is available to everyone you can use the APIs available to integrate the ED-516 in to existing software systems.

Integrating the ED-516 with software like Matlab and Labview will enable you to analyse production efficiency and future automation requirements. There are lots of possibilities and it all starts with simply counting boxes.