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Motion with PLCOpen

Motion with PLCOpen

Long-established Member


I am testing the promoter kit version RM20.07.
I want to move the real axis with the PLCOpen FBs.
There is a real axis declared in CtrlX with the name AxisX.

I insert the PLCOpen library and use the MC_Power Fb , but I have compilation errors (see attached).
How do I declare the Axis_Reference?

How to manage an axis created in CtrlX from PLC engineering with PLCOpen?
Thanks in advance.

Established Member

Hello David,

This problem is caused by library version.

You can solve this problem this way:

1. open "Library Manager" --> Placeholders

2. check version of CXA_Utilities you are using now, the rigth version should be or later.

Another thing in your "PLC_PRG":

name of AxisX should be assigned at the begaining, code like this: AxisX.AxisName := 'AxisX'; // AxisX is axis name you defined on web browser

Long-established Member

Thanks LiuPengfei for the reply.

The problem is that my CtrlX PLC engineering version 1.4.0 cannot update the CXA_PLCOpen library to a higher one.

The current and maximum version is

How can I upload the version of this library?

Thank you.

Established Member

Hello David,

Generally, the compatible version of all plc libraries will be installed during installation of ctrlX works.

In your plc project, PLCopen library is the newest version that we released. But the problem is CXA_Utilites, the version you are using is which is a very old version and CXA_PLCopen is not compatible with it (because CXA_PLCopen will use it internally).

So, I my recommendation is to upgrade the CXA_Utilites to CXA_Utilites has already been installed in you PLC Engineering enviroment if your installation of ctrlX work successfully. Left mouse click on CXA_UTILITIES, then all versions will be listed, select the newest version.


If you can not find CXA_UTILIES, repair installation of ctrlX works may work.

Long-established Member

Hello LiuPengfei,

I have managed to update the CXA library to version 1.2. The problem was when I was using a project from an old configuration.

Now I am trying to move the axis with the PLC_Open library but I get errors when compiling (picture attached).

I think something needs to be instantiated.
What could be the problem?


Established Member

Hi David,

The problem is still CXA_Utilities, you are using version of now (it mainly caused by you old plc project).


You can set to the right version by following step:

1. open "Library Manager" in the device tree;

2. mouse left click "Placeholders";

3. mouse left click line of "CXA_UTILITIES=CXA_Utilities, Rexroth AG)", then a version of will list below this line;

4. select CXA_Utilities,;

5. rebuild, every thing should be done;

Good luck.


If you want an example I made one with PLCopen some months ago. With some pictures..  ->

Maybe you allready saw it .

Regards, Stefan