How do I do "Control Point Stationing?"

Firstly, if you need help with control point theory or accuracy topics, please see below:

• Understanding what control points are and their importance: please see this article
• Understanding best arrangements of control points on jobsites: please see this article
• Understanding stability topics for total station accuracy: please see this article
• Understanding how to troubleshoot bad control points: please see this article.

Make sure your control point data is Imported correctly

Before you can attempt to station your unit by using control points, you must first have either imported or manually created the coordinates for your control points in your controller. Please make sure you data has the control points correctly labeled.

An easy way to check if you have control points in your data that are ready to be stationed with, go to CAD view on your tablet:

Then, open your point list from the side menu:

Then, filter just for control points by pressing the filter icon at the top of the points list and pressing the green check mark:

Lastly, see what remains in your point list and verify that the information is correct. Control Points will show up as triangles in your data set. They will be points at specific coordinates in your data, and the software may even have a specific prism type associated with them, depending on how the control points were established in the data.

If any of your control point data seems incorrect, please refer to this article to troubleshoot with your team. Remember, incorrect control will lead to an incorrect layout. If your control points are simply not labeled as a control point in your point list, it is easy to edit your point list and re-categorize any point you need to a control point.

Prepare Properly for Working with Heights (if applicable)

If working with height data (rather than just 2D) is important for you on this project, it is recommended you read this article to make sure you understand how station with heights. It will explain height of rod, benchmark height, and station height topics.

Open the Control Point Stationing Application

When you have confirmed that your data should be correct on the controller, navigate to the Control Point stationing application on you home screen.

Select your Control Points and Measure

This step is simple, as you are dimply measuring what is available to you, but there are three core things to remember before officially measuring your control points:

1. Make you have the correct control point selected
2. Make sure you have the correct prism or target type selected
3. Make sure the total station is targeting the control point selected

If any of the above three things are incorrect, you will not get accurate control point measurements, and therefore will not get an accurate station for layout.

To select a control point, you can either select it from the side point list, or simply tap the control point right from within the CAD view:

If the target at the top of the screen is incorrect, for whatever reason, change it to the target type that is associated with the control point you are measuring:

If you believe you may have measured the incorrect point, don't worry. You can always go back and remeasure any control point during this process before you accept a stationing. Simply select that control point again and re-measure it.

Analyze your Measured Data for Control

Observe the recommended layout area based on your tolerance

After measuring each control point, you will notice that they will turn either green or red, depending on your tolerance settings. Please see this article to understand what the tolerance setting is. You can always adjust your tolerance setting from the right window.

If you see red points, you know that the point was measured with an error greater than your tolerance setting. If it is green, it was measured with an error that is within your tolerance settings. These are visual cues to help you know where issues might be.

You will also see a green tolerance circle. This, also, is based on your tolerance setting. The green circle will indicate the layout area in which you can be confident to layout to the level of accuracy your layout tolerance is set to. See this article for more information on how this green circle can be useful to you.

Find the best recommended control points from the measurements tab

By opening the measurements tab, you will see the control point data that you have measured, as in the example below:

The deviation value information shows you how much the software had to adjust the point from its measured location to make it fit the design the digital file was looking for. Notice that for the point "CAT-4," it was  impossible to use in the stationing calculation. This point, in relation to the other points measured, was impossible to realistically fit to the way the design called for. This point was too far off its designed measurement (200 mm at least) to even be considered.

Notice that you can manually select the control points you would like to use as part of your stationing calculation, or, you can click "Suggest best selection" to have the software find the optimal points to use that seem to be  the most accurate.

Notice that when we clicked "suggest best selection," the software found the control points that could be used with the least amount of adjustments required. It removed "NAGEL-1" from the calculation, giving the widest layout circle possible according to your tolerance.

Again, you can click on the points you prefer to use in your calculation manually; the end user always has control when it comes to layout.

Observe the deviations between points

On the bottom right of the screen, under "Station Details," you will see the option to turn on "deviations between points."

This is extremely convenient to inspect whether or not  control points you have measured are accurate to the design.

Notice that the software will show how far off the points are between themselves based on the expected horizontal distance the design calls for, saving you time from going back to check these deviations some other way yourself.

Press the green checkmark when you are satisfied with your results

Simply press the green check mark in the bottom right of the screen when you are satisfied with your stationing results. Your head unit will now be given a specific coordinate, representing where it is located on the jobsite. It will know its location and its orientation, ready to guide you in your applications.