Autocad LT for Wi-Fi Engineers – Managing Layers

Are you a Wi-Fi engineer who received a CAD file to perform design on Ekahau but couldn’t because of the sheer number of layers slowing down the software or making it hard to understand the floor plan after importing? You are not alone. If Wi-Fi designing is part of your job description, this is something you often come across and a lot of the times, a CAD engineer is not easy to find to assist with cleaning the file. I faced similar situations and decided to identify a good software that can help me do the clean up. I evaluated a number of free open source as well as proprietary software and identified Autocad LT as a great fit for Wi-Fi design engineers. LT version of Autocad is supported on both mac and windows with retail price of $420 compared to $1690 for the full version which offers much more capabilities and features but are not necessarily useful for Wi-Fi designing. In this blog post, I will be describing how to manage layers to clean up the floor plans and best optimize for AP placements using Autocad LT for Mac.

Autocad LT provides multiple shortcuts for each operation. Once you open the CAD file using file -> open or cmd + O, using cmd + 4 shows the layers tool on the right which can be popped out into new window by clicking on the top right corner of the tab.

Displaying Layers Tab with CMD + 4

Clicking on any object on the floor plan shows the layer to which it belongs. Some layers are hard to read due to the choice of color. It can be changed simply from the layer property as shown in the video below.

Change Color of a Layer

If your file has tens of layers, an efficient way to browse the list is using the search window at the bottom.

Using Search Tool to Browse Layers

Once you identify the layer you would like to modify, you can select it and perform different operational tools. We focus primarily on four layer tools (highlighted from left to right)

  1. Freeze
  2. Turn off
  3. Lock
  4. Unlock
Layer Tools

You can perform them one layer at a time or on multiple layers by selecting them using cmd + click. The first two operations freeze and turn off can be used to disable or hide layers on the floor plan. Visually both these operations give the same result. But it is important to note one key difference. Turning off a layer will disable it for the current instance and re-appears whenever the file is reopened. On the other hand, freezing a layer will result in Autocad releasing it from memory. The layer will still be available to be thawed (unfreeze) at a later point if required. A frozen layer will not be shown on the map while importing on Ekahau whereas a layer that is turned off will be visible. Another layer tool available is lock. Locking a layer will prevent users from making any changes to that particular layer where unlocking will enable editing. Ekahau site survey sometimes have difficulty reading locked layers. So it is recommended to have all required layers unlocked.

These operations can be performed in a couple of ways.

  • Select the operation highlighted in the above picture and next click on any object of the layer you want to apply to.
Using Layer Tools – Option 1

or

  • Select the layer in the list and perform the operation using the tools in the same row with a simple click. The freeze and lock are intuitive on UI but turn off is shown under “visibility” (eye icon) of the layer properties window.
Using Layer Tools – Option 2

Please note freeze operation cannot be performed on currently active layer meaning the layer you are currently working on. To perform this you need to make some other layer as active. In the video shown below, I tried freeze layer “01” but it was active.

Changing Active Layer

Freezing all unnecessary layers will make the floor plan look more legible and easier to create AP placement maps on Ekahau.

Mentioning about an Ekahau Pro caveat I noticed seems to be a good way to finish this blog post. During one of the design exercises, I noticed the software was not reading some layers while importing. Opening a case with Ekahau revealed that the software does not detect layers without a Poly-object, poly-gon, poly-line or poly-circle. Ekahau support mentioned these are the basis for which the Wall Outlining Wizard allows you to configure as a wall (such as drywall or brick wall). So if you notice the same issue when some layers are not detected it is possible due to missing poly object. The workaround would be identify the layer, make it active and add a poly line from the draw tool on the left tool bar. This is demonstrated in the video below. In this video, it was assumed that the title block layer was not being detected on Ekahau because it was text only layer.

Drawing a Poly Line

Reference:

CAD file from https://www.cadblocksfree.com/en/4bhk-design-second-floor-plan-.dwg.html

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