This so called "ILDA connection" is a rather old transmission method, however it is used for nearly all computer controllable laser systems at the moment.

As the ILDA signal is a parallel transmission, the computer control signal (which is serial) needs to be converted to ILDA. This is done by the so called DAC (Digital Analogue Converter), which is also called "USB Interface" or "USB box" in combination with laser software. The parallel signal can only transmit one type of signal. It is not possible to address different lasers and give them individual control signals with one DAC. Do do so, you need additional DACs (one for each laser that should be controlled individually). However, the same ILDA signal can be used by many laser projectors - but they would do all the same.

To reduce the need of DACs, we suggest to link the ILDA signal of some projectors. Please see our setup suggestions for details: Laser projector setup suggestion

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Differences to DMX:

DMX is only a control signal that triggers the "intelligence" of a fixture. This "intelligence" has been previously set on the IC in that unit. Due to that, the fixture is limited to the functions that are pre-programmed. For normal fixtures, like moving lights or color changer, this is completely sufficient.

The DMX signal is a kind of a bus system that transmits in a serial way. It has a range of 512 adresses (that's why it's called DMX512) and each address can have values between 0-255. This shows that the DMX protocoll is rather simple and is not able to provide any complex information.

A laser projector needs a lot of information in real time to be able to draw complex graphics or beam projections. That's why it's necessary to have a much more powerful control option than the DMX standard.

In DMX you can easily address the fictures to certain channels to provide individual control options for these fixtures.
Show laser systems need an individual control signal per laser projector due to the quite low-level, but highly fequented protocoll. 

Conclusion:

- Showlaser projectors can not be assigned to an individual address and then called by the computer
- There is a 1:1 relation between the DAC (Digital Analogue Converter) and the Laser 
- Several lasers can use the same ILDA signal from one DAC, but they do all the same then
- By x-ing some pins, the signal can be switched -> Y-Adapter to connect two lasers which then act x-axis mirrored, but with only one DAC -> please see Installation & Setup hints