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7000 series readout system: Difference between revisions
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→Probe interface
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Most 7000 series plugins have [[BNC connector with readout ring|rings around the BNC input sockets]] that allow attached probes to interface with the readout system. The probe connector includes a contact pin connecting this ring. A resistor connected to ground encodes the probe attenuation, e.g. 11 kΩ indicates a ×10 probe and 6.8 kΩ a ×100 probe. If the probe includes an Identify switch at the tip, this connects the readout pin directly to ground. | Most 7000 series plugins have [[BNC connector with readout ring|rings around the BNC input sockets]] that allow attached probes to interface with the readout system. The probe connector includes a contact pin connecting this ring. A resistor connected to ground encodes the probe attenuation, e.g. 11 kΩ indicates a ×10 probe and 6.8 kΩ a ×100 probe. If the probe includes an Identify switch at the tip, this connects the readout pin directly to ground. | ||
The [[Media:Tek-plugin-readout.jpg|plug-in circuit]] uses the shift instructions in time slot 1 to implement the change of range, which is done by adding 100 μA (1 step) to the column current in time slot 1 for a ×10 probe, or 200 μA (2 steps) for a | The [[Media:Tek-plugin-readout.jpg|plug-in circuit]] uses the shift instructions in time slot 1 to implement the change of range, which is done by adding 100 μA (1 step) to the column current in time slot 1 for a ×10 probe, or 200 μA (2 steps) for a ×100 probe. For example, if the encoded unit was 100 mV, TS4 would encode a "1" digit, TS-8 the "m" prefix, and TS-1 the "add two zeros" command (R3/C2). Connecting a ×10 probe adds 100 μA in TS1, selecting the "shift prefix left" command (R3/C3) instead of "add two zeros". This drops the extra zeros and changes the prefix "m" to none, thus the display changes to "1 V". With a ×100 probe, the command selected would be "shift prefix left and add one zero" (R3/C4) and the resulting display becomes "10 V". | ||
===Complex plugins=== | ===Complex plugins=== | ||