The Transmitter section accepts bi-phase TTL data at the input and when coupled to the data bus with a 1:2.5 ratio transformer, isolated on the data bus side with two 52.5 Ohm fault isolation resistors, and loaded by two 70 Ohm terminations, the data bus signal is typically 7.5 Volts P-P at A-A' (See Figure 5). When both DATA and DATA inputs are held low or high, the transmitter output becomes a high impedance and is "removed" from the line. In addition,