Devicenet help

I am new to devicenet, but not entirely new to PLCs. I had a class back in college...

My project is simple (or so I thought) and I am having a heck of a time getting information on how to get things working. The background: I have a customer who is using devicenet on their line with barcode scanners. I am looking to help them replace their older scanners for 2D models. Our 2D scanners do not interface with devicenet - RS-232 is my best option. I have an AB Micrologix 1500 and the devicenet scanner module. I also have a couple of different devicenet to RS-232 converters to try.

What I need to do, is demonstrate that the PLC can send a trigger to the scanner using devicenet, the scanner reads the label information and sends the label information (text string) back to the PLC. I cannot find any good information on how to configure/program the devicenet scanner to send the trigger. Any one else have experience with this?

I have done bidirectional ASCII transfers with DeviceNet/RS232 interfaces from DIP Inc, Western Reserve Controls, and Allen-Bradley (1734-232ASC) using the SLC and the MicroLogix.

How this is done depends entirely on the DNet/RS232 converter. Exactly what models and versions do you have available ?

The models of the D-net/RS-232 converters are:

1. WRC 1782-JDC - Web address http://www.wrcakron.com/devicenet.html

2. CAN232 # C117 - Web address http://www.can232.com/

These were the 2 best priced units in a small package - one din rail mountable, the other an inline dongle type.

Next.... exactly what ASCII strings need to come and go from the barcode scanner ?

This could become a good "1782-JDC User's Group" thread.

I happen to have one of those and a MicroLogix 1500 LRP and 1769-SDN on my desk this week.

Also, I don't think the CAN232 is going to do what we want.

I have been prodding A-B to see if they can license something like the CANUSB to supplant the 1770-KFD for years, but nothing has come of it. The next generation of DeviceNet scanners from A-B will probably have USB network access ports on the front anyway.

"Next.... exactly what ASCII strings need to come and go from the barcode scanner ?

This could become a good "1782-JDC User's Group" thread.

I happen to have one of those and a MicroLogix 1500 LRP and 1769-SDN on my desk this week."


The ASCII Strings are going to be dynamic. The barcode scanner is reading the label information back to the PLC for exporting to a database and logging the serial numbers and part numbers (and other information) to ensure that what was supposed to be printed is actually printed.

That is the full assembly line application. I need to be able to demonstrate the capability of the scanner to do this and so I will probably use a smaller variety of labels.

If the CAN232 will not work, at least it was cheap!

Try this:
http://www.hms-networks.com/eng/products/products.asp?PID=105&ProductType=AnyBus Communicator

I've used the Communicator for Ethernet/IP a few weeks ago. The principle for Devicenet is the same. You could communicate with explicite messaging or Polled.

What kind of PLC do you use? PLC5? Explicite messaging is done here by BTR/BTW instructions.