Tektronix TG700, Руководство пользователя

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Operating Basics
Table 2-3: Pin assignments of the 10 BASE-T connector for the mainframe GPI
Pin number Function Level
1, 2, and 3 Input
High > 1.4 V or open (connected to an internal
10 k
Ω pull-up resistor)
Low < 0.4 V or ground (input impedance:
10 k
Ω )
6 Output Low < 0.4 V or ground (when sinking 100 ma;
maximum on-resistance 4
Ω )
Recalling a Preset
When you enable the mainframe GPI, you can recall one of the seven presets by
combinations of signal levels for pins 1, 2, and 3 of the 10 BASE-T connector.
The following table shows the combinations of signal levels for the pins and the
preset number to be recalled.
Table 2-4: Signal level combinations and the corresponding preset for the mainframe
GPI
Pin 1 Pin 2 Pin 3 Preset number
High High Low 1
HIgh Low High 2
High Low Low 3
Low High High 4
Low High Low 5
Low Low High 6
Low Low Low
7
All of the input signals are active low. When the signal level(s) for the speci fi ed
pin(s) goes from High to Low, the corresponding preset is recalled. For example,
when the signal level for pin 3 goes from High to Low, preset 1 is recalled.
NOTE.
Since the signal transition cannot be detected on the edge of the signal, the
signal level needs to be held low for about 0.5 seconds before the preset signal is
recognized. The time required to change the instrument settings depends on the
contents of the selected preset.
TG700 TV Signal Generator Platform User Manual 2–35