A key advantange to the Hog 4 OS is that you don't have to worry about the technicalities of how each lighting manufacturer implemtents the features of their lighting fixtures because the Hog 4 OS acts as a layer between you and the lighting hardware, automatically converting ‘abstract’ ideas of intensity, colour, and so on into the specific instructions that the fixtures need, defined by their DMX protocol.
The Hog 4 OS treats every fixture as a single entity. Every fixture is assigned a user number that allows users to easily recall a fixture and manipulate it's feature set no matter how many parameters it has. For more information on giving your fixtures custom user numbers , see Assigning User Numbers to Fixtures.
Hog 4 OS treats conventional lights, consisting of a luminaire controlled by a dimmer, as a special kind of fixture known as a ‘desk channel’. A desk channel has only one parameter: intensity.
Fixture parameters are described as far as possible in real world units. For example, rotation is described in degrees while chases are described in beat per minute. This speeds up programming and allows fixtures of different types to be selected and adjusted at the same time: for example, you can assign several fixtures of different types to all strobe at 10 Hz without having to worry about the different DMX values required by each fixture to achieve this. Hog 4 OS will give you the best possible match between fixtures; the only limitations are those of the fixtures themselves.
Some fixtures put more than one parameter onto a single DMX address. For example, a fixture might use DMX values in the range 0-127 for intensity, 128-250 for strobe, and 251-255 for fixture reset. The Hog 4 OS separates such functions into independent parameters, so that you do not need to remember the detailed workings of a particular fixture; in the example given above, the intensity, strobe and reset functions all appear as separate parameters, so there is no possibility of going from strobe into reset. With parameters that share a DMX address, changing the value of one will override the value of all the others, since there can only be one DMX value. In the case of our example, assigning a strobe speed will override any intensity value; the console will show a ~ in place of the intensity value to indicate that this has happened.
Any fixture already programmed into a show can be replaced by a fixture of a different type at any time and Hog 4 OS will as far as possible convert the programmed data to apply to the new fixture type. If the new fixture has more limited capabilities than the old one, this is handled as gracefully as possible. For more on replacing fixtures, see Changing the Fixture Type.