Ethernet/IP and PCCC PLC-2 messaging with labVIEW

[zmorris]

I am using labVIEW 2011 

Industrial Communications Add-on (Ethernet/IP) 

I have a device on the 232 side of an AB 1761-NET-ENI which only supports DF1 PLC-2 485CIF style read/write messaging. The typical application is to connect to a PLC on the ethernet side of the ENI.

I am attempting to create a test application with labVIEW to work in place of the PLC for pre-shipment style testing. (Each unit gets tested)

My first thought was to use Ethernet/IP to the ENI from labVIEW and messaging. The problem I quickly ran into was that the Industrial Communications Add-on does not appear to support the PLC-2 style messaging. I was hoping to keep the test simple with just a laptop and an ethernet cable to confirm that all the downstream wiring/configuration and ENI setup was correct. (Functional test).

Does anyone have any suggestions on achieving this without extra hardware or an OPC server? 

Thanks for any suggestions.

-Zach

[dwisti]

this post might help:

http://lavag.org/topic/6104-industrial-ethernet-ethernetip/page-2#entry87444

[zmorris]

At a quick glance it looks like it could be useful. I will check it out. Thanks dwisti.

[dwisti]

That code was only tested with a PLC5. The glossary of terms in Allen Bradley's EthernetIP protocol are tremendously confusing.  I have no idea what PLC-2 messages are but PCCC is DF1 commands wrapped up in a packet, aka CSPv4.

[zmorris]

http://samplecode.rockwellautomation.com/idc/groups/literature/documents/rm/1770-rm516_-en-p.pdf

7-31 PLC-2 unprotected read and unprotected write if you are interested. The device I am talking to uses those. The example isn't a perfect fit to what I am doing but with a little modification it might work.

[zmorris]

I made some modifications and tested with unprotected read, so far so good. I will post back again when I get a chance to do unprotected write. 

Thanks 

[dwisti]

Thats good news for anyone having to use a 1761-NET-ENI and some of these low end Micrologix controllers.  Which controller are you connecting to on the RS232 side?

[zmorris]

The controller is made by the company I work for (weighing industry) and still has legacy support from older versions using df1, it is fairly low volume so not much use for the community from that point of view. However, like you said still useful for other devices. The only thing I have done so far in the PCCC example is to change up the PCCC structure. Removing function code and such to fit unprotected read needs for my controller. Still I bet the same concept would work just fine for a MLX1000. May have to try it out later.