FireWire: Two Konnekt interfaces + PowerCore on one bus

Question

Is there a way to connect 2 Konnekts and also use an PowerCore FireWire on one FireWire bus?

Answer

It depends on the amount of channels you wish to run and the sample rate, as well as the type of audio interface.

The FireWire bus is devided into two types of data "sub-busses":

  1. Isochronous.
  2. Asynchronous.

1. The isochronous (ISOC) part takes care of audio.

The FireWire chip that used in TC audio devices -- DICE -- is able to listen to up to 4 ISOC streams at the same time. Most FireWire cards or build-in FireWire solutions also has this limitation, but you can actually get FireWire cards that are able to listen to more than 4 ISOC streams.

With DICE, each ISOC stream can carry up to 16 audio channels.

The ISOC channels have a quarantined bandwith, which means no matter what other traffic happens on the bus, the audio channels will always pass through. The TC interfaces (and most if not all other audio FW interfaces) use the ISOC part for audio.

All TC interfaces are transmitting using 1 ISOC stream, except for the Studio Konnekt 48 which uses 2 ISOC streams (since Studio Konnekt supports up to 32 audio channels).

2. The asynchronous (ASYN) part takes care of other kinds of data.

PowerCore uses the asynchronous part of FireWire for its communication. The bandwith of the asynchronous part is not guaranteed. This means that the ISOC part has priority over ASYN, and if there is bandwith problems -- or if too much data is congesting trying to get through -- the ASYN stream will drop out.

Besides PowerCore, you will find that external harddrives, video cameras and other devices use ASYN streaming.

Summing up: the answer is yes, but you might run into bandwith troubles, depending on a couple of things:

  1. How many PowerCore plug-ins do you use at the same time?
  2. How many audio channels do you stream?

The fewer audio channels you stream and the lower sample rate you use, the more reliable system you have.

It is possible to run two audio interfaces together with PowerCore, however, we recommend that you put your audio interface on a seperate FireWire bus, to avoid interference between the devices.

To add another FireWire bus to your system, simply buy a second FireWire port / card. These are quite cheap, and will generally give you a much more stable system.

Please note: Although it is possible to use multiple Konnekt devices simultaneously, using multiple devices in a single "I/O network" at 88.2 / 96 kHz and above, aren't possible.


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