How to Read a Data Matrix Code

Use the Read Data Matrix Code step to locate and decode a 2D Data Matrix code.

Main Tab

1. In the Step Name control, enter a descriptive name for the step.
2. Choose one of the following methods to specify the region of interest for the step:
   • Create a new region of interest.
     1. Select Constant from the Region of Interest listbox.
     2. Select a tool from the menu toolbar that matches the type of region of interest you want to specify.
     3. Draw a region of interest on the image.
   • Select a previously defined region of interest from the Region of Interest listbox.
3. Verify that the Reposition Region of Interest control is enabled if you want to link the region of interest specified in this step to a previously defined coordinate system.

   Link the region of interest to a coordinate system if the position of the object under inspection changes from image to image, and you need to adjust the position of the region of interest to match the new location of the object.

Basic Tab

4. Set the controls on the Basic tab to specify the shape of the Data Matrix code and improve the performance of the step. Select the Suggest Values? control if you want the step to suggest values for the controls when you click the Suggest Values button.
5. Select the Return Grading Results checkbox if you want the step to return AIM grading metrics for the Data Matrix code. If you do not need grading information for your application, disable the Return Grading Results control to decrease the amount of time the step takes to complete.

Adv. Search Tab

6. Set the controls on the Adv. Search tab. Select the Suggest Values? control if you want the step to suggest values for the controls when you click the Suggest Values button.

Cell Sampling Tab

7. Set the controls on the Cell Sampling tab if the step cannot consistently read the Data Matrix code because of variations in lighting or quality. Otherwise, use the default values for the controls on this tab.

Limits Tab

8. To compare the decoded data to a constant, select the Code Equals control and enter a string that the decoded data must match.
   
   To verify that the Data Matrix code contains a specific string, select the Code Contains control and enter the string.
   
   To perform character verification on the Data Matrix code and set the step result based on the verification grade, complete the following steps. On the Basic tab, enable the Return Grading Results control. On the Limits tab, enable the Minimum Overall Grade control and select the minimum grade you want to use.
   
   The decoded characters the step read are shown in the Code Read control. Additional information about the Data Matrix code is returned in the Results table.