The 2228NT is a VS TC Synchronous Null Modem designed by Thomas Junker that uses a standard 10BaseT RJ45 patch cable to connect two VS synchronous communication ports. This replaces bulky 25-pin RS-232 cables and the difficult to find Wang 2228N or 2229N Synchronous Null Modem.

The 2228NT consists of two parts, "A" and "B". Each is a DB25/RJ45 adapter. The "A" adapter contains the synchronous clock injection from pin 11 while the "B" adapter contains the crossover connections. Each connection between a pair of VS TC IOC RS-232 ports must use an "A" adapter on one and a "B" adapter on the other.

Based on the Wang 2228N, the 2228NT distributes synchronous clock from the injected source (the TC IOC to which the "A" adapter is connected) to both the Tx and Rx clocks of both TC IOCs. Thus the "A" IOC determines the link speed. VS TC IOCs and outboard DLPs may be jumpered internally to inject synchronous clock on Pin 11 or Pin 24. Pin 11 is the more common usage and the one required by the 2228NT.

RTS from each side provides CTS to its own side and DCD to the other side. DTR from each side provides DSR to the other side. TxD, RxD and the unified clock signal are paired with ground or signals that do not change.

Because crossover is done in the "B" adapter a standard straight-through 10BaseT or better patch cable may be used to connect two VS systems for WSN or other purposes. Care should be taken not to interconnect VS TC ports with standard network signals.

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