MELSEC find IO

mike_dr

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Sep 2011
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Mla
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I have a PLC with ff rack config: Q03UDCPU , Q12DCCPU-V, QX41, QY40P. main is Q312B
in GX works 2,I cannot find the tag Y1023 in the ladder but I found Y23. Is it the same tag? any tips for finding it?

and another question, why is there a K4 in BMOV K4x1000 K4B500 K9 when you can use just X1000 B500 yes? sorry newb here
 
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I am familiar with RSlogix5000, already used cross reference to find Y1023 but is not found. I got the tag from a keyence VT studio HMI so I might be wrong here. so where in the IO rack should/can this be found?

full rack is Q03UDCPU , Q12DCCPU-V, QX41, QY40P, QY40P,QY40P, Q68DAIN, QJ71C24N,QJ71BR11,QJ71BR11 - (last 3 which all comm modules)
 
Those are not the same tag those are separate Devices.
There are a few different ways to find a device or tag. You can click Find/Replace in the top tool bar. Clicking Cross Reference should pop up a menu in the bottom of the screen. Typing the "label" in the Device/Label box and pressing find will show you all its instances.

Most the tools in the Find/Replace menu could help you with finding this. If you have done much PLC stuff it should start looking familiar from there.

So the K4 thing is a little more complicated.
K basically means a decimal number.
X and B are single bits. So to group them together into words of any bit length you can designate them in the command with a K value.
An easy way to find how many bits in that groups is multiply it by four.
So K2X1000 would be 8 bits
And K8X1000 is 32
BMOV is a block move so you cant use single bits you have to group it into words.
The last value is how many words to move in the block.

So this means BMOV K4X1000 K4B500 K9 is moving X1000 through X1008 into B500 through B508.
X is an input and B is a link relay to another device with a CPU.
So this is most likely moving the input status at X1000 over a network to the other PLC. To try to put it plainly.
I will get you some manuals that will probably help more than me rambling.
 
Also highlighting a command and pressing F1 will open the manual to that commands explanation and examples.
Help in the top menu bar has some manuals as well.

Here is a few manuals that will help get you started. Its a steep hill you are about to climb haha :)
GX works 2 Starting manual
http://dl.mitsubishielectric.com/dl/fa/document/manual/plc/sh080787eng/sh080787engp.pdf


There is a free online class I used to learn Mitsubishi q series I will try to dig it up and get you a link.
 
I think the tag from keyence/VT studio is defined in a different manner in GX, thus I cant find it easily like the other tags im looking for.so it's two hills for me to climb lol
 
I hope I didn't take you the wrong way there, I misunderstood your system and your experience. I hope I helped with the K4X1000 thing
I would think they would still show up in the Cross Reference.

Give me a min here I don't have the software in front of me and I don't want to tell you something misleading.
 
thanks for the BMOV explanation, I did find the help but didnt read the K4 so its a very helpful post Mits.
 
The Q12DCCPU C controller is cool, I have not used one of those but was reading on them the other day. Over my head but cool. Its that that has me hesitant with out the software in front of me.

If nobody has solved this for you when I get to my other PC tomorrow Ill try more to help.

The X1000 could be a MelsecNet Assigned Device have you checked in the network parameters under Network Range Assignment.

Is the keyance connected to the Q12DCCPU-V?
 
is there an effect in the Input/output definition in VT if keyence is connected to CPU-V?

I do not know for sure and I do not want to speculate since I am not familiar with that setup. I havnt used one of the CCPUs.

I can try to help make sure its not in the network settings but probably not much help today past there.

When your on that screen you sent the shot of there is a drop down that says switch screens if you drop that down it should have some other possible devices, If I am remembering correctly. Maybe some X and Y set there.

One other area to check is the network refresh area. In the network params screen under where you selected Network Range Assignment there is a tab for Refresh Parameters could be in there.
 
One other thing I cant remember what it is called for the life of me. Hopefully you can follow me here

When you drop down the Find/Replace menu there is another selection right under or above the Cross Reference. Device Setting.. maybe...
If you click that it pops up a window similar to Cross Reference that will tell you if those devices are used in any parameters or not.


I have to get off here. Good luck to you.
 
im following you. im found that window for used parameters and that tag isnt also used. thanks for the advice again Mits

I found out in VT studio that the model that keyence vt3-s12 is connected to is QnU series CPU direct, port 2 if that would help
 
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So I have looked through the software and found some stuff on the Multiple CPU setting,

If the goal is to find out where Y1023 is coming from there is one more area I know to check, but if you go find/replace then click device list it should show up in there.

I guess how do you know it exists at all? Like what is your reason for finding it? Is it in a drawing or in the keyence vt3-s12 set up?
Also what do the comments say for these devices that may give some insight to where they are from.

So go parameters then double click PLC Parameters.
First look at the I/O assignment tab you can set any start address for a card so lets make sure Y1000 is not start for the output card on the rack.

Then lets check some of the multiple CPU settings.
So under PLC parameters click the Multiple CPU Setting Tab
Top left selection will tell you if it is set up as a Multiple CPU set up. (I think it should be)
If that selection is 2 than see if any of the two boxes are checked on I/O Sharing When Using Multiple CPUs.

The two tabs on the right hand side one says, Multiple CPU High Speed Transmission it has some devices assigned if you click refresh it is possible to set Y as a device in there.

The other tab Communication Area Setting (Refresh Setting) this tab can also have some devices assigned.

All of this said, I have not ever not had a device show up in Device List that was used anywhere in the project.

I hope you have found the answer all ready and you don't need any of this!!
 
Y1023 has comments in GX works and is used in the keyence HMI as a lamp switch which is my guess why its not in the program.

in the IO assignment, i dont see 1000 http://prntscr.com/enqgp0

In the multiple CPU setting, it does say 2 PLC but IO sharing not checked. I guess that's it. it doesnt have any input in comm area setting. having said that, I guess no other PLC can control this via messaging/ethernet so the only culprit is local PLCs and HMI.
 

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