# Controlling feature geometry using control codes

Use control codes when you want more control over the shape of the linear or polygon feature you are measuring.

Trimble Access uses the same control codes as Trimble Business Center to create line, arc, or polygon features from points. Points that have the same line or polygon feature code assigned to them are joined by lines. Trimble Access does not fill polygons.

To create features as you measure, select the feature code for the point and then select the appropriate control code from the CAD toolbar.

The CAD toolbar works in two modes: Measure mode and Drawing mode. When you have started a survey and open the Measure points, Measure topo, or Measure codes form, the CAD toolbar automatically switches to Measure mode.

For a detailed step-by-step guide to creating features using control codes in the Measure codes form, see To create features using control codes in Measure codes. This topic also highlights key differences when creating features using control codes in the Measure points or Measure topo form.

Once you are familiar with control codes, refer to one of the following topics for a handy guide when in the field:

- Quick reference: CAD toolbar with Measure codes

- Quick reference: CAD toolbar with Measure points or Measure topo

## Feature code library requirements for control codes

To create features, the feature library must contain codes defined as lines for the features you want to create, and control codes for the required action to create the feature geometry, such as starting or ending a new join sequence. The example codes in the Trimble Access Help are found in the GlobalFeatures.fxl example feature library file that you can install with the Trimble Access software using Trimble Installation Manager. See Example feature library file for installation.

Start join sequence control codes start lines, and End join sequence control codes end lines. You can use one or the other, or both, depending on the situation or workflow you prefer as there is flexibility in how you use them. For example, you can start lines without a control code, but to start the next line of the same feature code type you can use either the End join sequence control code on the previous/last measurement, or use the Start join sequence control code on the first point of the new line.

For example, to survey the centerline of a road, the feature library must contain a road centerline (RCL) feature code defined as a Line feature type. To create the centerline feature, before measuring the first point in Measure codes select the RCL feature code and then tap the start join sequence button on the CAD toolbar. All subsequent points with that are assigned the RCL feature code are added to the line.

Where there are more than 2 points in a sequence before the line is stopped or a control code is used to skip or join to another code, feature coded linework creates a continuous line segment or polyline. The linework is not saved to the job as a polyline, but created on-the-fly from coded points. The polyline can be selected and staked. Or, to select an individual section of the polyline, tap and hold on the individual section of interest and then from the tap and hold menu select Select feature coded line segment.

## Assigning multiple codes

You can assign multiple feature codes and control codes to a single point. When assigning more than one feature code, the simplest way to select multiple feature codes is to use the Multi-code button in the Measure codes form. First tap , and then select the feature code and the control code(s) to apply.