Acknowledge erc errors

Is there a way to acknowledge ERC warnings ?

For exemple. I have a tri-state pins that are connected to an output
But, in my configuration, the considered tri-state pins is always and input and will never conflict.

Is there a way to reconfigure the pins role on a particular component or acknowledge a particular type of erc error on a pin so it does not generates an error each time ?

For the moment, the only solution I found to avoid the erc errors is to add 0 ohm resistors between the two. which is kind of ugly.

In KiCad V5.1.x there is no way to do this. The workarounds I know are:

  • Adding zero ohm resistors is possible, but they will be components on your PCB. Ouwtch…
  • You can use a net-tie. This is also a PCB footprint, but just a piece of copper, and no BOM entry etc.
  • You can change the pin type: First make a personal library, then copy the symbol to it and change the pin type of the offending pins, and use the modified symbol in your schematic.
  • You can change the ERC matrix to not complain (but this disables all warnings of that type).
  • You can ignore it and live with the ERC violations.

In KiCad-nightly V5.99 you can right-click on an ERC violation and then choose “Exclude this Violation”


I can safely do this in this situation, because the violation is for two outputs of RS485 drivers in DIP and SOIC packages, and only one will be placed on the PCB.

Eeschema remembers these exclusions, (Even when closing KiCad) and you only have to tick them off once. You can make them visible by checking the “[x] Exclusions” checkbox, which shows them in grey, and then you can also “Un-exclude” them again:

Yes, there is. What you’re actually lookin for is a bidirectional pin.

Strictly speaking, a tristate pin doesn’t have any input functionality. The three states are high, low and high impedance (H, L, Hi-Z). Note that there’s no input state (as that isn’t even a state)

If a pin can be an input and output, then it’s bidirectional. The output driver for the pin has to be tristate, since it mostly doesn’t make sense to read back the value you output. That doesn’t make the pin tristate, as that category is reserved for output only.

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