AudioRail® is a daisy chain network with time division multiplexed (TDM) streams of up to 32 channels of audio traveling in both directions at once (64 channels total) on any one cable. At each node in the network, digital audio is inserted into or extracted from the TDM stream.
The ADAT rx32tx32 transports the Alesis ADAT Lightpipe digital audio format.
Look at the pictures below, which show signal flow (not real cables) depicted using gray arrows through a couple of Category 5 cables in an example configuration of three AudioRail units. This is just an example, and it will be broken down into simpler diagrams.
The picture above has several simultaneous signal paths configured in an example daisy chain of 3 nodes, showing the routing flexibility of the system, entirely configured by front panel push button switches. ADAT Lightpipe stream A is being sent from the input on the left AudioRail unit to corresponding outputs on both other units. On that same channel, Stream B is being sent from the input on the right AudioRail unit to the corresponding output on the left unit. Stream C is being sent from the right AudioRail unit to the middle one (but no further), and on that same channel, stream D independently goes from the middle unit to the left unit. Stream E is being sent from the middle unit to both other units, traveling in both directions at once.
The following illustrations will break the scenario above into some simpler components, for the sake of better explanation of the functional possibilities.
In the picture above, an ADAT Lightpipe input on A on the left is configured using front panel switches to go to the right. On the middle and right units, a switch will select the corresponding A outputs to come from the left.
AudioRail has two completely independent paths on the CAT5 cable, one going in each direction, each being capable of 32 channels of audio (4 Lightpipe's worth). In the picture above, the ADAT Lightpipe input on B on the right unit will be configured using front panel switches to go to the left. On the left unit, a switch will select the corresponding B output to come from the right.
The above picture shows that a signal need not travel along the entire daisy chain. It can travel over just part of it. A front panel switch on the rightmost unit is pushed to send the C lightpipe input to the left. A front panel switch in the middle unit is pushed to get the C lightpipe output from the right. Another front panel switch in the middle unit is also pushed to send the D input to the left. Note that this is the same lightpipe channel as on the right unit. It is still only taking 1/4th the bandwidth capacity of AudioRail in that direction, leaving all the other channels free and available. The input D replaces what could have been stream C continuing down the daisy chain, and keeps C from going further. Then a front panel switch on the unit on the left AudioRail unit selects D to come from the right.
The above picture shows that a lightpipe stream can be sent from one input to go both directions at once. Two front panel push button switches on the middle unit are pushed, selecting the E stream to go both to the left and to the right.
A sound system designed around an AudioRail CAT5 network can be very versatile, in terms of its routing ability, the length of the CAT5 cable segments (up to 100 meters, or 328 feet, each segment), the minimal thickness of the CAT5 cable, and manageability of a CAT5 cabling scheme.
Each ADAT Lightpipe output stream follows the timing of its source (44.1K/48K, or 88.2K/96K with ADAT channel doubling format), making each connection appear as a virtual wire in a digital audio snake.