Has anyone successfully used NI-DNET with Allen-Bradley Flex I/O modules?

[knorcross]

I recently found out that the DeviceNet scanner card I have (A-B 1784-PCDIS) is not supported by the NI-DNET drivers (and developing a LabView driver is beyond my scope right now), and was wondering if anyone has used the NI-DNET scanner card with Allen-Bradley 1794 Flex I/O modules.
It would be nice to be able to tell my manager that there would be no problems configuring and reading/writing data to the Flex I/O modules before I hit him up for an additional $1000.00 for the NI card....

Thanks,
Ken Norcross

[biker2000]

Hi Ken

Yes, the NI-DNET hardware and software will be able to communicate with your AB Flex I/O modules as with any other DeviceNet slave. However, as far as I know, Allen Bradley does not document how the DeviceNet slave objects are built out of the attached Flex I/O modules, in fact the address of the objects changes when you swap two flex I/O modules.
Thus, you wound still need the A-B 1784-PCDIS scanner card to run the RSNetWorx software to discover the Flex I/O slave and find out how each I/O modules needs to be addressed.
Once you know that you can use the NI-DNET software to configure slave and use it for I/O.

-B2k

[Lorna Slater]

I use Labview with Allen Bradley CompactBlock IO and it works great. Wire it up to the NI-DNET card, apply 24VDC and the Labview 'simple who' will tell you how to talk to each block. Just read and write to them, no additional hardware or RSWorks required.

I'm using 1790/D/P CompactBlock LDX I/O both analog and digital base and extension blocks.  I think they need to be set to poling mode to work properly, but you can fiddle around with it, and use NI-MAX 'self test' to clear the handles if the software crashes or something.

Lorna

[gyachts]

Has anyone had success with the 1794-AENT/B ethernet modules?  I have one of the Flex I/O ethernet interface modules with two 8 port analog in modules.  I can read the 1794/AENT module information like model, version etc but nothing representing the I/O data.

Greg

CVC

[malocascio]

Sorry to drag up an old thread, Greg, but did you ever find a way to do this? I'm now presented with the same problem, I need access to channel data from a 1794-AENT over its EtherNet/IP interface. Might be open to adding a DeviceNet card if it works.

[gyachts]

The way I ended up doing it was by installing an AB PLC in the network and using it as a concentrator.  The AB PLC could pole all the different Flex I/O I had on the network and then my National Instruments program would request the data from the PLC.  It actually worked very well and I could have multiple PCs running the Labview code all talking to the one PLC.  I also could store calibration data in the PLC and then all PCs used the same calibration data.

Hope this helps.

Greg

[malocascio]

Thanks, Greg. We were hoping to get away with something simpler and cheaper than a PLC, but if that's the only way around it, we'll manage. Thanks for letting me know.

[MrJackHamilton]

I know this post is old, there is a very cost effect solution for a PLC that can interface to LabVIEW. Look at Velocio.net. They make some FPGA based PLC modules, with a very impressive range of I/O including thermocouple. They can also to PID control.

They can interface with LabVIEW either via ModBus [RS232 Serial] or via simple serial:provided you code this into the PLC.

Regards

Jack Hamilton

[gyachts]

That's great info, I'll look into it.

Thanks.