SLC 500/Micrologix Ethernet/IP simulator emulator

[PJ_Cell]

Hello,

I am using the Ethernet/IP Driver for Industrial Communication on a project. Everything is working great.

The PLC, Microligix 1400, is supported by another vendor. I am using the SLC Read and Write functions.

When doing upgrades, it would be nice to be able to simulate reading and writing to the PLC.

Does a product exist that could do this?

Or, even better, is there documentation on how I could write a Labview program to do this so I could return specific values based on what was written?

Thanks,

P

[Jesse_D]

Hi PJ, 

You could write to a different computer or cRIO with EIP installed. 

Just be aware that the LV EIP toolkit doesn't have implicit scanning capabilities. That means that while you will be able to use explicit communication you wont be able to use implicit. 

If you do get a simulator up and running though let us know how you did it. I think other people would be interested in what works well. 

[PJ_Cell]

Hi Jesse,

I'm not sure I follow you.

My dev machine has the EIP driver installed. I set it to a static IP address that matches the PLC in the field. But my app returns 'Unable to connect to the network path specified'.

I assume I would have to write a prgram that is listening on a certain port and perform handshaking and exchange data, but I have nowhere to start on that.

PJ

[LewisL]

Hi PJ,

1. I don't understand what you mean by "When doing upgrades, it would be nice to be able to simulate reading and writing to the PLC."

2. “I set it to a static IP address that matches the PLC in the field. But my app returns 'Unable to connect to the network path specified." 

If you can ping PLC for the LV machine (or another PC) then the IP is correctly set.

3. You don't have to write low layer program to do handshaking. 

Maybe when I have a big picture of what you are trying to do then I might be of aid.

Lewis

[dwisti]

---

PJ_Cell wrote:When doing upgrades, it would be nice to be able to simulate reading and writing to the PLC.

Does a product exist that could do this?

Or, even better, is there documentation on how I could write a Labview program to do this so I could return specific values based on what was written?

Thanks,

P

---

Its my understanding that the Labview EthernetIP toolkit can not perform the function of a PLC (i.e. scanner).  Labview can only act as a adapter.

[Jesse_D]

That is right. The toolkit cannot act a an adapter for implicit communications, it can for explicit communication though. 

[dwisti]

---

@Jesse_D wrote:

That is right. The toolkit cannot act a an adapter for implicit communications, it can for explicit communication though. 

---

Interesting... then it should be possible to create a simulator in Labview.

[PJ_Cell]

Thanks for all of the feedback so far.

I'm trying to get up to speed on the terminology i.e. scanner/adapter. I assume we need to create a scanner.

How could one use the tookit to create an app that would respond to the SLC500 Read/Write functions in the toolkit?

Could someone whip up a vi with some of the basics as a starting point?

PJ

[sahpe]

Hey PJ,

If you can program a PLC, then it might be worth utilising its own simulator and communicating between LabVIEW and that. I believe you would be looking for "RSLogix Emulate" in this case.

I don't see a point in simulating the handshake, that's pretty straight forward, why test its simulation? So I wouldn't bother with that, but for testing your PLC functionality or logic, then research the above and see if it gives you an easier way.

Hope this helps a little.
Kind regards,
Michael S.

P.s. asking people to write you a VI doesn't generally go down very well in the forums 😉 but someone might surprise me and prove me wrong! You never know...

[PJ_Cell]

Hey sahpe,

Thanks for the suggestion. I have programmmed AB PLCs a lot in my time and I will look into that.

The PLC program I am interfacing to is pretty simple. I turn 4 valves on and off and read about 10 sensors. I just want to return specific values just so that I know it is going to work when connected live.

I actually found a site http://iatips.com/digiwiki/quick_eip_demo.pdf that seems like it could get me going, but the Labview toolkit sends a message that doesn't match this example or the Rockwell description of the PCCC protocol http://www.rockwellautomation.com/resources/downloads/rockwellautomation/pdf/sales-partners/technolo... The 'Register Session' is the same and I can reply to that, but the 'Unconnected Send SLC500 Read' is 15 bytes less and I can't see how to  decode it yet.

I wouldn't ask anyone to write my code for me. I was just trying to understand how one could use the toolkit to communicate with the toolkit.

PJ