Automated wire numbering in EPLAN Electric P8 is certainly a great time saver. I’ve worked with 500+ page projects, and I wouldn’t want to go back to use AutoCAD.

While EPLAN is certainly flexible when it comes to wire numbering, sometimes a specific customer requirement leaves me pensive, and sometimes it becomes a challenge I have to accept.

In this example, the customer wanted all connections to motors to be numbered like this:

where the format is <Page number><Non-digit part of motor connection point designation><Counter per motor per page>

The picture above shows a proof of concept with two motors on page 2, and their corresponding desired wire numbers. The more motor on a page, the higher the last digit(s) of the connection designation. I’ve tested my solution with 12 motors on a page with the correct result.

Connection numbering scheme

The idea is to create a connection numbering scheme that defines a format group based on specific devices, in our case the motors, or devices with “MTR” as their DT identifier (note that in some cases the DT identifier for motors might be only “M”, so this would have to be tweaked):

I placed that group at the top of the list so that those connections in that group are considered first when numbering. Once a connection is handled by a format group, it is not handled by groups further down the list, so you have to go from specific to general (top to bottom in the list of format groups).

This is how the group is defined:

The selected format elements are:

  • The Page name of the target component.
  • A block property defined on the connection currently being numbered (described in details below).
  • Then finally a subcounter defined over the signal/state of the connection (in our example, the same number on each side of terminals).

Here are screenshots of their specific settings:

Block property format for connections

Block property formats can be defined at the individual connections, but it’s better to define them globally in the project.

Under Project > Properties…, you can select the Formats from the Category drop-down in the Properties tab. This will limit the number of properties displayed in the grid.

Add those two properties to the grid:

Block property: Replacement text [1]:


Block property: Format (connection) [10]:


The replacement text table is defined like this:

It’s important to note the Operator is set to Regular expression on all 3 rows. Then the Source text is the actual Regular expression to evaluate, and the Output text is what we want to replace the match from the RexEx with.

The RegEx is used to detect which pin of the motor we are connected to, and then use “U”, “V” or “W” accordingly.

The block property format is defined as follows:

Last function via connection point and target number (PLC), Connection point 1, Target 1: Name of target connection point (Full),

and then the Replacement text is set on the block property format:


By defining a block property format for connections at the project level, we implicitly assign it to all connections of the project.

The block property format “pulls” the Name of target connection point (full), meaning that it will return something such as:


And then using the replacement table and its regular expression, we convert that to simply “U”.

In the connection numbering scheme we have defined the Page, the Block Property, and a subcounter.

All together, those pieces of data form the connection designation as wanted by the customer.


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Registration is required, but free. If you have questions about this, or any related topics (or unrelated), don’t hesitate to ask there.