Datastorm Controllers and their functions
by Don BradnerThere have been three different major versions of the Datastorm controller since the Datastorm was introduced. This article describes each of them.
Alternate names: LCB, LCB-1. Was not known as D1 until the introduction of the D2.|
Introduced: Fall, 2001.
The D1 is a "dumb" controller, with all of the intelligence provided by Datastorm software running on a Windows PC. The attachment between PC and controller is an RS-232 serial cable.
The Datastorm software, in turn, gets all of its satellite information from Direcway software running on the same computer, referred to as the host. The most common modem in this arrangement is a DW4000, a "dumb" modem, although it is possible to use a 4020/6000/7000 with some difficulty and workarounds. If you are contemplating such a combination, ask in the forums here for advice.
Method of satellite search: Same as D2, see below.
Introduced: Summer, 2004.|
The D2 is a "smart" controller, with a built-in computer that replaces the Datastorm software running on a host. It is a network device, and communicates with modems via the network; it therefore requires a network-capable HughesNet modem and will not work with a DW4000.
While the D2 is smart, it does not have a satellite receiver, and relies on a HughesNet modem to provide information about satellite signals.
Method of satellite search: The D2 modem uses GPS to calculate the azimuth, elevation, and proper skew for pointing to the selected satellite. The azimuth value is coupled with a compass reading to determine the amount of rotation required.
Because the compass is rarely accurate, and issues such as tilt can affect accuracy as well, the configuration of the controller/software includes a "window" that it will search around the assumed satellite position. That window defaults to 25 degrees wide by 10 degrees high.
When a search is initiated, the dish is elevated to the expected value, skew is applied, and the dish turns to the beginning of the window. From this point on, the dish is moved in 1-degree increments, with small pauses after each move to query the modem for signal value.
The dish continues to rotate until a signal of 31 or higher is seen, or the end of the window is reached. If the latter occurs, the elevation is increased by 1 degree and the search continues backwards through the window. This pattern continues: 2 degrees down, 3 degrees up, 4 degrees down and so on, moving back and forth across the window until the signal is found.
If the full window is exhausted without finding the satellite, the window is widened to 180 degrees and the search is begun again.
Introduced: Fall, 2005.|
The D3 is a "smart" controller coupled with a sensitive DVB satellite receiver. It does not require any modem in order to find a satellite, but will interface with a HughesNet modem if one is present and the Direcway/HughesNet mode is selected in the controller's configuration.
Method of satellite search: The D3 modem uses GPS to calculate the elevation, and proper skew for pointing to the selected satellite. Azimuth and compass pointing are ignored. When a search is initiated, the dish is elevated to the expected value, skew is applied, and the dish turns steadily until a signal is found that is higher than a threshold value, set in the controller's configuration.
When a signal is detected, the controller compares it with an internal table of known satellite signals. If a match is found, but is not the desired satellite, a calculation is made to determine where to move to find the proper one, and both azimuth and elevation are changed as needed. In most cases that will be the final search, but in some cases another incorrect satellite will be found, resulting in another move as needed.
Beginning with firmware version 3.8.9, a D3 in Datastorm/HughesNet mode will stop searching when the modem reports a signal above 31. In this case, the modem is immediately used to peak the signal, reducing the amount of time for a given search.