Overview

NC-Var Selector is a utility provided by the Siemens installation material that retrieves addresses of required NCK variables. This is accomplished by generating files, one of which is a .awl file containing the symbol and address information that can be used in Simatic Manager to generate a data block DB120 containing this information. We will then later use this data block to to retrieve them with FB2/FB3 in a PLC program.

Configuration Steps Overview

1. Select variables with the NC-Var Selector tool

2. Save selected variables in a *.var file

3. Generate a Step7 *.awl file

This process is done in preparation for the machine configuration process for 840D SL which is described in it's own article here.

NC Var Selector - Selecting Variables

Once opened, the NCVar Selector presents the user with a list of all variables in the NCK.

Where do I learn more about NCK Variables?
Brief description of the NCK variables is in the NC-Var Selector utility on each data item through opening them.

More complete descriptions of NCK variable can be found in the SINUMERIK 840D sl/840D/810D/840Di SIMODRIVE 611 digital/SINAMICS Lists (2nd Book) manual.

Where do I learn more about Sinamics variables?
Unlike NCK, Sinamics parameters have virtually no description in the utility without drilling into each numbered drive individually. Descriptions can be found in SINUMERIK 840D sl PLC Function Manual.

In this article we are going to use the MachineMetrics provided .var file as a base. From the navigation bar, open the new file by selection Open from the menu dropdown.

We will select MM Siemens Tiav18 NCVAR.var from a location on disk and then be returned to the NCVar Selector utility. Here we can see in the bottom window that the default values have been loaded for us.

We need to identify which data items in the NCK we are interested in targeting for monitoring. For this article we will walk through adding Torque values for 3 drive axes that are stored in the SInamics tab and identified as r0078 - torque actual current.

Note: The values for Sinamics parameters can be found in the SINUMERIK 840D sl/840D/810D/840Di SIMODRIVE 611 digital/SINAMICS Lists (2nd Book) manual.

First we switch to the Sinamics tab in the top window editor

Which will present us with the list of all Sinamics values we could potentially target.

We want to filter the available list for the parameter we are interested in, so we click the filter button.

This opens the filter dialog, we input r0078 into the Name text field provided for the filter and then click the OK button.

We are then returned to the NCVar Selector main panel and we can see that the top panel as been filtered to only show the r0078 parameter.

By double-clicking on the r0078 value in the top pane, we can add it to the .var file shown in the bottom pane. Double-click on r0078 and we will be presented with the data item info pane

 

Scrolling down in this pane we can see further description of r0078 which is similar to the information presented in the parameter manual.

We are interested in r0078[1] smoothed curve for this value and we will start with Drive 1. To do so we input 1 into Area No. for the first drive. We leave Row as 1 for the index.

We click Insert into Project and the parameter is added to the bottom window pane.

We repeat the process above for drives on axis 2 and 3, inserting them into the project.

We can observe in the S7 Alias Name column that NCVar Selector has generated symbol names for these parameters.

These symbol names do not do a very good job of communicating what these values are. By right clicking the symbol we can rename it by clicking the Rename a variable of the project.

We assign a set of symbol names that better communicate the data items. 

We press OK to commit the change. We then repeat the above symbol rename process for each other variable.

Here we see the result of all 3 symbols with their improved symbol names

With all of our torque values selected, we now need to generate the updated .var output file.

First, we save our updates from the top ribbon, press the Save button. This will save the updates we have made to .var. Alternatively you can Save As from the Project menu on top to create a new file separate from the initial file.

Then we generate the .var file from the top ribbon by clicking the Generate button

Choose a good name for the updated file, here I have suffixed the original filename with MyCompany to retain and distinguish it from the default.

Having saved this file to a known good location on disk, it is now prepared for import into the TIA Step 7/Simatic Manager project.

For more information about the next steps on how to configure the 840D SL machine for MachineMetrics data collection, see this article.

If you have questions about this process, please reach out directly to your customer success manager or contact support@machinemetrics.com.