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How to connect Variables to I/O?

How to connect Variables to I/O?



I'm completely new to ctrX programming, but did Siemens, Beckhoff and Mitsubishi in the past. So I know a bit of PLC programming. That said, I still have trouble with something I would say is basic...

Please correct me, if I do things wrong, but I thought I had to code my PLC program in the ctrX PLC Engineering and my hardware in ctrX I/O Engineering!? Because I have not the slightest idea how to "connect" those two? 

I have my in/out variables in a variable-table on PLC side as:

var_1 AT %Q* : BOOL;

and so on. So... how I can I tell my I/O config that they are there?

In the manual for the PLC engineering and the part about I/O config I found a screenshot of the "device" tab with a PLC and a DPMaster and a few devices on there. Aside that I have EtherCat, do I not need I/O Engineering? Do I all in PLC Engineering? And if so: How? Because I can't find a way to include any communication-master there. I can do that in the I/O Engineering without a problem. 

So: Can someone tell me, what I do wrong or where to look where that is explained how to do? I'm a little bit lost...

Thanks in advance!


Long-established Member

Hello @TBauer ,

have you seen this How-To ?

Yes, for EtherCAT you need the IO Engineering .

In the PLC ENgineering you have to click with right mouse button on the datalayer to edit the entries.

The ypu will see the %IX...   and so on:





Here you will also find this info (an example).  In the Datalayer you will find the IOs also without PLC App.

But to use it in the PLC that helps:

See Point 3) and 4)

That helps and I know what to do now!

Two things about that:
Interestingly you don't have to mark your variables with "AT %I*". It is not working when you do that! That is confusing for me 🙂 

Also I have a ctrX Core next to me, so I can "download" the configuration from there. But there is an option to do it "offline from file". Maybe could be relevant in the future... Can I create that file from I/O engineering? There is an "PLCopenXML export" but that doesn't seem to be it (PLC engineering says "wrong format") or I mark down the wrong structures. Any hints for that? 

Community Moderator
Community Moderator

Please have a look to this topic about offline IO configuration and import.

You can use the "AT %I*" for mapping variables or input the variables directly in the IO are of ctrlX PLC Engineering.

Long-established Member

Hello @TBauer ,

just if more information regarding %IX.. / QX... is needed, but CodeShepherd allready answered:

Yes, that's working as for example: