AB contrologix devicenet

Good day ladie and gents.

I had a scanner go bad but I have a saved configuration (.dnt) that was originally downloaded to the scanner. I thought I could just download the saved configuration file to the new scanner and it would work but under the network drop down box “download to network” is grayed out and won’t let me download. It will let me go online but the new scanner (node 63) appears obviously. Do I just delete the new scanner and then download? Do I need to reregister the devices because the eds file has never been saved on my computer.

I often say that DeviceNet is a little like swimming; if you take a couple of lessons before you jump in, you are a lot less likely to drown.

In general, to replace a DeviceNet Scanner like the 1756-DNB, you need to configure its basic settings (Node Number and Data Rate) and then download the Scanlist to it from an RSNetworx project that contains that scanlist.

The 1756-DNB modules conveniently have rotary switches along the top edge of the module for setting the node number and the data rate.

The EDS files for the slave devices aren't necessarily needed to do such a download; all the identity and memory mapping information are part of the Scanlist.

All you need to do to download the Scanlist to the 1756-DNB is select the DNB in the RSNetworx graphical schema, right-click and select "Download". It might be labeled "Download to Device"; I don't have the software handy.

The "Download to Network" feature (that you can access from the menus or by right-clicking on blank space in the graphical display) should only be used if you have a fully backed up and correct RSNetworx project file; it goes around to all of the devices that are in the project file and downloads their offline-saved parameters. If they haven't been uploaded or don't match the devices, you can often end up loading the EDS defaults, which can badly screw up your network if you get unlucky.

Background: what sort of symptoms/evidence do you have that your 1756-DNB failed ? They are often the most reliable and well-protected device on a network.

Thanks for the reply Ken.

The network consists of 5 limitorq actuators and the scanner. The scanner and 4 of the devicenet cards in the actuators were bad. I’m assuming due to a lighting strike or some high voltage that was induced into network. The file I had saved was a .dnt. I’m assuming this file is of the whole network as you mentioned in your reply? I opened the file with rsnetworx and went online after trying to “download to network” after installing new scanner with correct node address that I manually changed before installing. After going online I performed “download to device” on the scanner. Then I selected “download to network” and all of the actuators failed to download because of identity errors. I could not get rid of the errors until I installed eds file for actuators. Could you explain more about eds file and it’s purpose? I thought it was just a text document that explained IO mapping for the device and wasn’t needed for communication to work

You can check out the below guide

https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/22309

Thanx for sharing.

jcole28, do you believe the risk of damage through lightning is a matter of concern? Is there any segment of the DeviceNet bus laid in-between buildings where it may be more exposed to lightning? In such a case you may want to consider using fiber optic to CAN converters so the exposed segment is replaced with fiber. You would need to have a DeviceNet power supply for one of the segments, so this change would require some electrical engineering, but nothing would be needed on the PLC program or the RSNetworx, I believe,