Suggestion: Some way to not schedule for specific items

[brainfart21]

I tried to make the LTN equivalent of an active provider chest and kinda hacked it by requesting a single item and adding it along with the trash I wanted to get rid of at the provider, as the train would otherwise not leave the station. It works fine, but it throws an error message because of the mismatched content, which is irritating.

I think a very simple way to do it would be with a negative valued virtual signal set at the request and the same positive valued signal set at the provider.
The train is then scheduled to listen to the virtual signal at the station and not from the train contents. This would also allow other things where the actual cargo is not of interest or unknown. I think this would be better than adding a map setting "Schedule item count conditions"

[Optera]

LTN is completely requester controlled.
As long as requesters keep up, active providers are easily achieved by higher provide priority.

It works fine, but it throws an error message because of the mismatched content, which is irritating.

The train was loaded with something not in schedule, so working as intended.

[brainfart21]

working as intended.

So what would be an intended way to get the behavior of an active provider chest or to request something only known at the provider in LTN? Technically requesting everything at the receiver could work, so that the train is scheduled to only pickup the items that are provided by the provider station. But then you need a combinator signal for every item in the game...