cr_drew

Interacting with QCPU Registers from LabVIEW or Raw TCP

10 posts in this topic

Hello all!

I am in a time crunch and must find a way to send a command to a few registers on a Q03UDVCPU from LabVIEW in short order.  Having never used Mitsubishi PLCs or GxWorks2, my understanding is that MC Protocol over TCP is likely my best bet.  Do this make sense, or am I missing an easier way?

The current interface is a GOT, but I need to update a few things programmatically from my embedded controller.  I have tried to use Wireshark on the Ethernet hub between the QCPU and the GOT, but only see a few "Who are you" broadcast packets.  Does anyone know why I might not be seeing the network traffic I expect?

Thanks in advance!

Drew

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An update, the switch itself is an OMRON W4S1-05B, and it looks like it is unmanaged.  The only configuration I found was a QoS switch to prioritize control data.  I tried turning this off, but it made no difference in the capture.  Any chance the CPU settings could be masking the comms from Wireshark?

The Wireshark capture is attached, it isn't much to look at.  I think 192.168.3.39 is the CPU.  Any ideas?

Q03UDVCPU-GOT1000.pcapng

Edited by cr_drew

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Also, I will probably end up needing a copy of GxWorks2.  Does anyone know where I can purchase/demo the software?  Mitsubishi's website is super confusing.

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from http://www.chipkin.com/hubs-vs-switches-using-wireshark-to-sniff-network-packets/

A switch will never forward 'other' traffic (traffic that is not directed to your ethernet mac address + broadcast) to your port unless you tell it to do so. So, if you did not configure a mirror port on the switch, you will only see this kind of traffic.

  • your own traffic
  • traffic to multicast and/or broadcast addresses

Please read the following Wiki article: http://wiki.wireshark.org/CaptureSetup/Ethernet

 

Basically you need an old hub not a switch (or a programmed managed switch) - personally I bought an old Netgear DS104 hub to use with wireshark which works great.

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looks like labview has an MX components driver. Also the  NI-OPC server support all Mitsubishi PLC's

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2 hours ago, Nightfly said:

 

from http://www.chipkin.com/hubs-vs-switches-using-wireshark-to-sniff-network-packets/

A switch will never forward 'other' traffic (traffic that is not directed to your ethernet mac address + broadcast) to your port unless you tell it to do so. So, if you did not configure a mirror port on the switch, you will only see this kind of traffic.

  • your own traffic
  • traffic to multicast and/or broadcast addresses

Please read the following Wiki article: http://wiki.wireshark.org/CaptureSetup/Ethernet

 

Basically you need an old hub not a switch (or a programmed managed switch) - personally I bought an old Netgear DS104 hub to use with wireshark which works great.

Fair point, I guess I thought the fact that it is listed as a switching hub meant it might be ok.  I have an el cheapo router that I have successfully used to capture EtherCAT traffic, so I will try to use that this morning and see what happens.

If not, do you think I could just plug directly into the plc and get anything?  I'll try this as well.

Thanks!

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3 hours ago, Gambit said:

looks like labview has an MX components driver. Also the  NI-OPC server support all Mitsubishi PLC's

Thanks for the reply!  It's actually interesting that this YouTube channel is basically the only mention of LabVIEW and Q PLCs online.  

I believe LabVIEW supports MX Component through ActiveX, I couldn't find a native driver anywhere.  Unfortunately, because I must control this via my embedded controller, I can't use ActiveX.

It is true that their OPC server will support Mitsubishi PLCs.  If it comes to this, that may be my only option.  However it seems like a ton of overhead to set up a whole server just to send a few commands.  Regardless, you are correct that it is an option.  Do you know if the OPC server supports PLCs natively, or if you must configure the PLC to talk to it?  My main issue is one of not knowing anything about configuring the PLC, nor currently having access to GxWorks.

For now, I think my focus will be sending raw TCP packets representing MC protocol frames, as the YouTube channel does in another video. Now I just need to figure out what messages to send the PLC.  I'm thinking Wireshark to scope the Ethernet connection, but having trouble getting packets to show up (see previous reply).

Thanks again for your reply!

Edited by cr_drew

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11 hours ago, Nightfly said:

Basically you need an old hub not a switch (or a programmed managed switch) - personally I bought an old Netgear DS104 hub to use with wireshark which works great.

This is my FAVORITE TOOL in my backpack.

http://www.midbittech.com/

Shark-Tap

It works with Wire Shark no problems. I have solved alot of problems with this, from Ethernet/IP, to ASCII over Ethernet, to Modbus commands, to just about anything that passes through my Shark-Tap box.

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On 8/3/2017 at 4:23 PM, Chris Elston said:

Shark-Tap

Ingenious!  I wish I had need of one enough to justify the price tag!

On 8/3/2017 at 7:45 AM, Gambit said:

Or you can check te manual

MELSEC Communication Protocol Reference Manual

 

Yep, that's what I meant by " sending raw TCP packets representing MC protocol frames".  

Anyways, I convinced my company that we needed the software to be effective at accomplishing this, so I have a copy of GxWorks and GTWorks on the way.  Thank you for y'all's help!  I'll be sure to post back when I'm neck deep in MC Protocol frames and can't find my way out :-2

Drew

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