I am having a lot of Diamond symbols in my schematic named as Pxxxx. I am not able to find what it means as there are no legends mentioned in the file.
Also, are there any general conventions that govern the usage of symbols in schematics?
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3\$\begingroup\$ It's just a net label. \$\endgroup\$– Eugene Sh.Commented Aug 29, 2016 at 14:02
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4 Answers
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Those look to me like testpoints. On an actual board they would either be empty pads or they may actually be testpoint components.
answered Aug 29, 2016 at 14:02
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\$\begingroup\$ Are test points typically indicated using this symbol? \$\endgroup\$– stenvarCommented Aug 29, 2016 at 14:08
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\$\begingroup\$ As far as I know there is not much of a standard for test points. Usually I see them as little circles with a wire connecting to them (radio-electronics.com/images/…) though using other symbols is not unheard of. It generally comes down to how the design engineer was trained and his/her personal preferences. \$\endgroup\$ Commented Aug 29, 2016 at 14:10
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1\$\begingroup\$ @SojuTVarghese ours look differently (sort of a triangle) and are labeled TPxx. I guess it's a company wide standard but not much more. \$\endgroup\$– ArsenalCommented Aug 29, 2016 at 14:11
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I'll hazard a guess that these are test points. These provide an convenient access to a signal. Test points are useful for debugging, quality control testing, calibration, troubleshooting. A signal can be probed at a test point. Or, a test signal may be injected into a test point to exercise the downstream circuitry.
On the PCB, a test point can manifest itself differently, depending on the expected type of test.
- It can be a throughole of surface-mount component for clipping a probe to.
- It can be throughole for sticking an oscilloscope into.
- It can be a surface-mount pad for automated test equipment.
As far as I know, there is no single standard schematic symbol for test points. Here are a few symbols that come with schematic software.
(from OrCAD)
(from Altium)
The standard designator for test point it TP (source).
answered Aug 29, 2016 at 14:04
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It's either a net label or a test point.
answered Aug 29, 2016 at 14:02
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\$\begingroup\$ sorry, but i don't get what a net label is..? \$\endgroup\$– stenvarCommented Aug 29, 2016 at 14:04
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\$\begingroup\$ A net label is simply a way of naming a net (a connection). This is especially useful if the net has a special function and you want the reader to know what it does, or in CAD work it is used for error checking and for converting a schematic to a PCB design (showing where components connect) \$\endgroup\$ Commented Aug 29, 2016 at 14:06
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2\$\begingroup\$ A net label just assigns a name to that wire so it can be referred to later on another sheet, on reports, in simulation, during board layout, etc. \$\endgroup\$ Commented Aug 29, 2016 at 14:06
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The test points could document locations for probing on a bed of nails functional/ICT fixture defined by a Test Engineer working with the Design Engineer for high fault coverage for fixture design.
