TB 9-6625-2089-24
b. Adjustments. Adjust A3R10 (fig. 1) for 30 μs (R).
14. Mode 4 Interface Input and Output Accuracy
a. Performance Check
(1) Connect equipment as shown in figure 3.
(2) Set pulse generator for a positive pulse of 1.5 V at 500 Hz and a pulse width of 0.5 μs.
(3) Set oscilloscope to display CH1 and CH2 and measure spacing between leading
edges of pulse on CH2 input and first pulse on CH1 input. Pulse spacing will be between
195 and 205 μs, if not perform b (1) below.
Figure 3. Mode 4 interface input and output - equipment setup.
(4) Measure pulse width of first pulse on CH1 input at 50 percent of pulse
amplitude. Pulse width will be between 0.4 and 0.6 μs, if not perform b (2) below.
(5) Measure pulse amplitude. Pulse amplitude will be between 4.5 and 5.5. V.
(6) Measure spacing between first and second pulses leading edge to leading edge.
Pulse will be between 1.7 and 1.9 μs, if not perform b (3) below.
(7) Set CHAL INHIBIT switch to ISLS ON and observe pulses on CH1 input are inhibited.
(8) Set CHAL INHIBIT switch to DISPARITY (MOM) and observe that pulses on
CH1 input are inhibited.
(9) Set CHAL INHIBIT switch to OFF and disconnect cable from pulse generator
pulse out jack. Observe that three pulse reply disappears from CH1 input.
