Auto-apply True Position Relationships using Standardized Characteristic Labels
This article explains the format to use to name you characteristics for True Positions.
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written: 08/21/2023
last modified: 04/26/2024

Some of our more popular machine drivers support automatic true position bonus relationships set up during data collection. These CMMs send enough information for QC-CALC Real-Time to create these relationships automatically.

For CMMs that cannot do this, we offer a way to get that information to QC-CALC Real-Time through the Characteristic Labels. QC-CALC Real-Time looks for a specific, standard format in the label, and if that format is detected, the encoded information is extracted, and the true position bonus relationship is applied.

Standard Label Format

QC-CALC Real-Time will look for characteristic labels with the following format: NormalLabel_TP0001_T_B

Note: The standard label format TP####_T_T, TP####_D_H, TP####_Y, etc., must come at the very end of the label. That is where QC-CALC will look for it.

where NormalLabel is your typical characteristic label. The key part is everything after the first underscore. TP0001_T_B is the standardized portion of the label that QC-CALC Real-Time will use to auto-apply the true position relationship. The 4-digit number is the identifier. The characters that follow the identifier (preceded by underscores) define the kind of TP relationship.

The identifier:

  1. Must be a four-digit number (e.g., 0001)
  2. Must have both starting and ending underscores (e.g., _TP0001_)
  3. "TP" must be capitalized (e.g., TP0001)
  4. Must be the same number in all characteristics that will form the TP relationship

After the identifier, there are either one or two characters, each with a preceding underscore:


This characteristic is a True Position with a base tolerance.


This characteristic is a True Position with a total tolerance (bonus included).


This characteristic is a Diameter and is a Hole or ID.


This characteristic is a Diameter and is a Pin or OD.


The circular TP scatter plot will use this characteristic on the x-axis.


The circular TP scatter plot will use this characteristic on the y-axis.

The characters above tell QC-CALC Real-Time whether the characteristic is a true position, a diameter, or whether to use the characteristic in a TP scatter plot (on the x or y axes)

For example, Feature 1_TP0001_T_T tells QC-CALC Real-Time that this characteristic is a true position and has a total tolerance (with an included bonus). QC-CALC Real-Time will use the information encoded in the label to create the appropriate true position relationship.

If you want Feature 1_TP0001_T_T to be applied to a TP relationship with an OD characteristic, then you will want to send the following label for the OD characteristic: Feature 2_TP0001_D_H

As you can see, the 4-digit identifier allows QC-CALC Real-Time to determine which incoming characteristics should form that particular true position relationship.

QC-CALC Configuration Options

There are additional configuration options in QC-CALC Real-Time for this feature:


When enabled, QC-CALC Real-Time will trim the label to remove everything after NormalLabel. This effectively gives you your original labels without the TP identifier and characters appended. QC-CALC Real-Time will still auto-apply the TP relationship defined by the label before trimming. To enable this setting, set the value to “1”; to disable it, set it to “0”.