Below the antenna pointing, the ACU shows the actual beacon level. There is also a strip chart display of the level. The chart moves with the same speed as the angle charts above, so you directly can watch the influence of tracking steps to the beacon level. A click with the right mouse button into the chart shows a pop-up menu for scales and other display options.
The screen also provides fields to set the beacon frequency and the receive polarization (the latter is not supported by antenna where the example picture has been taken from). Changing the values in these fields changes the beacon receiver setting immediately.
If you are using a third party beacon receiver which is not controlled by the ACU indoor unit, you nevertheless have to set the beacon frequency here. This is because the tracking software takes the frequency into account when estimating the antenna receive pattern and from this the tracing step sizes.