Modbus Connection to Barcode Reader


Thread Starter



I have case where I need to connect metal detector, which have Modbus TCP/IP card in it to the barcode reader.

Idea is that in metal detector there are several (app. 100) different product programs for different applications.

On each product there is barcode which include what products is. Products are going on the conveyor belt.

Barcode reader would read the barcode and based on that information it would change the product number on the metal detector to match the current product.

Here is citation from the metal detector manufacturer introduction:

"In order to change products remotely, all you need to do is enter the product number (using a program such as such as Modscan, PC Master, or other similar program) into Modbus register number 41045 and set parameter-change coil number 16385 to one (1). When you enter the product number in this register, all metal detector settings for this product are automatically updated, and the metal detector is now ready to start analyzing the new product you specified"

My question is, what do I need to do for implement this kind of action? Is it possible to connect metal detector and barcode reader to the PC which have e.g Modscan program?

Manufacturer couldn't give me detailed introduction how to do this.

Thanks in advance!
The set of tasks is too involved to provide detailed instructions, here, too.

It isn't clear whether the metal detector programs are identified by bar code value or some other 'arbitrary' product number. If different than the bar code value, then associating the bar code value with a product number might be necessary.

I suspect that most bar code readers have some utility program to get them to read in via USB or serial. The effort then is in linking the value the bar code reads to a Modbus program.

If I were doing it, I'd probably use a Data Station Plus because it is a Modbus master, it can read and capture a serial bar code, and it has enough horsepower to associate a bar code value with a product number, if need be.

There's a video using Red Lion's Data Station Plus to read from a serial bar code reader here

Others would probably use a PC.

If it turns out that this is beyond what you want to tackle, you can look to hire a "systems integrator" because this is what SI's do for a living (like the guy who made the video).
Thanks David_2 for you reply!

Metal detector have a Modbus register which contain different functions, but in this case only job would be change the product. All products are identified with simple product number (001, 002, 003...). So metal detector itself doesn't have any special product number which could be similar as bar code script.

So basically bar code library would be handled in bar code reader sw, if it's not possible to made some like in Modscan(?).

Yes, I think that I have to find some SI to solve this issue. I have asked few ones, but here in Finland it's seems that it's not so common to use Modbus any more.
If your barcode reader has an Ethernet or serial interface you could use our ETH-1000 gateway to read the barcode value from the barcode reader and write the product number to the metal detector.

For communicating with the barcode reader, the ETH-1000 supports both a generic socket (TCP/UDP) driver on its Ethernet port and a generic serial driver on its RS-485 port. These drivers allow any arbitrary protocol to be defined.

For communicating with the metal detector, the ETH-1000 supports Modbus/TCP Client. The gateway also supports internal logic operations that would allow you to associate barcode values with product numbers, if necessary, and perform the logic to set the parameter-change coil after writing a new product number to the metal detector.

More info on the ETH-1000 can be found here: