BNC connector with readout ring: Difference between revisions

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Most 7000 series plugins have '''rings around the BNC input sockets''' that allow attached probes to interface with the readout system.
[[File:Readout_ring.jpg|thumb|250px|right]]
[[File:Readout_pin.jpg|thumb|250px|right]]
Many 1970s/1980s Tektronix scopes and plugins have '''rings around the BNC input sockets''' that allow the attenuation factor of
attached probes to be detected by the scope.


The probe connector includes a contact pin connecting this ring.   
The connector of compatible probes, e.g. 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.   
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.  
* In most [[7000-series plug-ins]], the ring interfaces with the [[7000 series readout system|readout system]]. The [[Media:Tek-plugin-readout.jpg|plug-in circuit]] uses the shift instructions in time slot 1 to implement the change of range. <br />If the probe includes an Identify switch at the tip, this connects the readout pin directly to ground, encoding the special IDENTIFY instruction in time slot 1.
The [[Media:Tek-plugin-readout.jpg|plug-in circuit]] uses the shift instructions in time slot 1 to implement the change of range.
* Readout-less [[5000-series plug-ins]] and a number of standalone scopes of the same era, e.g. many of the [[400-series scopes]] such as [[485]], use the ring to detect a ×10 (but not a ×100) probe, and indicate the correct scale factor using front-panel lamps or LEDs.
 
* The [[7A14]] plugin uses the same BNC connector with a ring but the ring serves a different purpose, which is to detect the difference between the [[P6021]] and [[P6022]] probes, and switching in appropriate gain and frequency compensation.  The P6021 shorts this ring to ground, directly switching three relays connected to -15 V internally.
The [[7A14]] plugin uses the same BNC connector with a ring but the ring serves a different purpose, which is to detect the difference between the [[P6021]] and [[P6022]] probes,
and switching in appropriate gain and frequency compensation.  The P6021 shorts this ring to ground, directly switching three relays connected to -15 V internally.
 
Readout-less [[5000-series plug-ins]] and some standalone scopes of the same era, e.g. many of the [[400-series scopes]] such as [[485]], use the ring to detect a ×10 (but not a ×100) probe, and indicate the correct scale factor using LEDs.


==See also==
==See also==
Retrieved from "https://w140.com/tekwiki/wiki/BNC_connector_with_readout_ring"