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Ethernet/IP comunication with CompactLogix using Assembly Instances

I am somewhat new to LabVIEW and am working on a project where I am trying to communicate with a CompactLogix PLC using Assembly Instances.  I am running LabVIEW on a PC.  The PC and PLC are connected through a company network.  I have tried an example program and haven't had any luck getting it to work. 


I have created a very simple program for troubleshooting (see attached).  I have also attached my virtual ETHERNET-MODULE setup from RSLogix5000 program.


Does the ETHERNET-MODULE IP address need to be a unique address, or is it the address of the LabVIEW PC?  I don't have any logix in RSLogix5000 to send or recieve messages.  It doesn't appear I need these.


I don't have a preference for how I communicate with the CompactLogix.  This method just looked easy.

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Hi jwelcheck,


You only need to make the parameters match on two sides - Create Assembly from the examples (<National Instruments>\LabVIEW 20XX\examples\ethernetip\) and the PLC side.

Your VI has 1) mismatching assembly size - 32 bytes on VI side vs 64 *32-bit on PLC side ,  2) non-updatable assembly because nothing is set in the loop, and 3) missing the producing assembly. 


Implicit Messaging is for periodical update of assembly data. Explicit Messaging is for occasional, thus more service oriented.

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Hi Eric,


I'm new to LabVIEW. Is the IP address configured in RSLogix5000 Generic Ethernet Module the IP address of the LabVIEW PC or there is a place to configure the IP address of the NI EIP adapter in LabVIEW?




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