SR1 - Matrix Barrier equivilent?, looking through some friends old adventures Options

[Telion]

I'm running an old SR1 adventure and while I can convert most the stuff pretty easy from its SR1 equivalent to SR3, I'm failing to figure out what a Matrix Barrier is, from the sounds of it, its a reactive IC or some kind of System test, since I don't have a copy of SR1 or VR1.0 my research is slow going.

The offending Matrix system is pretty easy so I'm not to worried about creating my own interpretation, but the system is as follows:

The primary node with multiple slaves attached.
The slave is and Orange 3 Barrier 3
and the other is an Orange 3 Access 3

3 because they are connected via the console cutting down the TN.

Any old timers around?