PLC5/80C 1.5 to Flexlogic over CNET

[PeterW]

I could do with a little help understanding how the addresses are linked.

I'm having to check and probably modify an existing system which is consists of a redundant PLC5 system interfacing to a number of Flexlogic units (the Flexlogic is used purely as serial interface modules to other machines).

The interface is ControlNet via MSG instructions in the PLC5.

I can open the MSG and see as the pictures below:

But I cannot see how this data actually gets to the correct data in the Flexlogix. I know where it goes, a DINT[3] TAG.

The MSG indicates N10:0 as the destination address, I presume this is a dummy, as no TAG in the Flex has even been called N10:0.

I am missing the RSNetworx ControlNet project file that is linked in the CPU properties, does this have additional info that will link the data direct to the correct TAG?

I have other more modern projects doing the same thing (using ControlLogix PLC's) and of course the TAGS in the Flex are marked as Consumed in these. In the PLC5 project they are not as the PLC5 cannot produce.

Can someone gime me a pointer of where the link is firmed up, is it in that missing file?

 

[tomalbright]

Look in the IO hardware section, for IO mapping of the Cnet addresses - this will still be there if you don't have RSNetworx to get to the details.

It's kinda hidden, but it works. The data is mapped to the addresses in the IO file, the devices are basically just added as IO, no "smarts" out there.

 

[PeterW]

Thanks for the reply.

When I open IO Config, it shows the CNET as channel 2.

But when I open the properties, there is no channel 2 to look at, ethernet appears instead.

.

 

[tomalbright]

I had to fire up the laptop, but here's what I'm looking at:

Note that I DID have to have the XC file installed, but this is how it looks, Cnet to flex.

ETA: this is all standard IO, no serial stuff.

 

[PeterW]

When it opens up it does tell me it will create an empty CNET project as the file is missing.

OK, thanks. Confirmed what I thought.

 

[PeterW]

Got the RSNetWorx file and it was empty, had not been saved. Then did as I should have from step 1, asked a colleague.

If anyone else ever gets in this pickle, the here is the answer.

In the Logix5000 end, from the top pull down menu, select Logic - MAP PLC/SLC Messages.. and from there you get this.

As always, easy when you know how...

 

[PeterW]

I now realise that I have no idea how data is being passed back from the Flexlogix to the PLC5/80.

In the Flexlogix PLC data is put into a DINT[4] Array, which is set as a Produced Tag with 2 consumers. Which matches what I would expect as I have 2 PLC5/80's as a redundant pair.

The problem I have here, is the above mapping does not cater for this additional tag and the PLC5/80 MSG instructions are all PLC-Type Write (there are no read).

As the PLC5/80 does not have the capability to consume tags, where would I find the mapping for this?

 

[Ken Roach]

You were right about the correlation between your MSG Write instruction in the PLC-5/80 and the File 10 = SCN_Load_ID map entry in RSLogix 5000. That's an unscheduled message and is the ordinary way for a Logix controller to emulate PLC-5 messaging.

One detail; I think the SCN_Load_ID tag should be an INT[x] array if it is to match up with the data you are sending from N95:0,1,2 in the PLC-5/80C15.

It sounds like your system is also using another mechanism to transfer data from the FlexLogix to the PLC-5/80C15 pair.

The PLC-5/80C15 does have the ability to "Consume Tags" on ControlNet. The difference is that from the PLC-5/80's perspective they aren't tags, but rather Produced Data Objects.

Scheduled ControlNet data exchange between Logix and PLC-5C15 is complicated, and Logix -> PLC works slightly differently than PLC -> Logix.

 

[Ken Roach]

You're going to see the PLC-5C15 ControlNet "Receive Data From" buffer that corresponds with the FlexLogix Produced Tag defined in the ControlNet Scanlist Tool in RSNetworx for ControlNet.

This mechanism is described (better than I can do it) in RA Knowledgebase Article ID # 19290.

 

[PeterW]

Thanks, gives me something to follow now.

I have a feeling that there may be another PLC/PC in the mix somewhere, as the result data I'm looking for appears to come in one of 5 integer buffers, N90: to N94: all named Buffer.Rec and all 42 integers long.

I'll read up and see what i can find.

Thanks again.