Labview as a Master A-B PLC as a Slave

[zerocover]

I would like to use Devicenet to connect labview, using the NI-DNET PCI card as a master, to a A-B PLC with a 1769 scanner module as a slave. I have been able to connect to the Devicenet using labview as a slave and everything has worked smoothly.

To get the master to work I have reconfigured the A-B plc and removed labview from its scanned list, so that labview is no longer its slave. Now when I look into RSNetworx it shows labview and the PLC as slaves w/out a master. What do I need to do to set labview as the master, other then setting the devicemacid on the open IO vi to the mac of the PLC in this case 1?

[Mr.F]

Hi zerocover,

According to this link, the dnet device usually functions as master. Did you change this setting somehow?

http://digital.ni.com/public.nsf/allkb/FF5A2B77E6F12BF04825717300086F4C?OpenDocument

Also, just to clarify, when you say make LabVIEW the master, are you refering to the NI-DNET PCI card? Take a look at that KB and post the eds file that you're using.

Thanks,
Matt

[illiniengineer]

It sounds like you missed one final step...  In RSNetWorx, right-click the scanner module, select "properties", select the "Module" tab, and then the "Slave Mode" button to enable and configure the scanner.  I think there might be an EDS file at ab.com for the 1747-SDN in slave mode, for loading into NI-DNET.

Mike

[zerocover]

To Matt W.

To clarify when I say Labview I mean the NI-DNET pci card.

I'm using the NI-DNET 1.5 eds file from the link you have posted (Its where I found the eds originally) could this be my problem? I had written the labview code for the Ni-Dnet card to be a slave on the network, and that works well. However I have more complex things to do now and would like to change the code for the NI-DNET card to be the master.

From everything I've read this should be as easy as changing the devicemacid part of the DNET open vi to the mac of the PLC. However when I do that I still have labview as a slave.

To illiniengineer
I left out that I had already enabled slave mode through RSNetWorx. Since doing that the 1769 comes up as a slave in RSNetWorx, however it is also listed as the master to labview. This is what makes me think its a problem with my labview code.

[Mr.F]

Ok, thanks for the clarification. Using that eds might complicate things if you are also trying to explicitly tell the DNET device to be a master. I’m curious about how that would interact with RSNetWorx. I’ll ask around tomorrow about it.-Matt

[Mr.F]

Hi zerocover,

Switch the device macids is not all you have to do to change the master/slave relationship. I’m not sure about the RSNetWorkx part, but with LabVIEW you can configure the DeviceNet system in Measurement and Automation Explorer. If you are getting errors trying to configure your network through other means, please attach a screen shot or two and a spy capture. This will let me take a deeper look into your problem.

 

-Matt