I think I'm just doing something wrong here, but i've had an issue with requesters locking up because there's a trickle left of what its requesting so it won't send a new train. I have to manually empty the remainder to get it to ask for a new train. Is there a setting for this, or some way to set up a station so it doesn't have to wait until it's ABSOLUTELY empty to request?

For reference, this is a station setup for a uranium mine requesting Sulfuric Acid for the mining process. It's a four wagon stop that uses eight pumps to empty directly into four tanks for a total capacity of 200k acid. When each tank is emptied, it shows 0.1 acid and the signal is reading as 8 acid left so it won't request a train. I imagine I can circuit up some kind of if/else circuit to round the acid number down if it's ten or less. But it would be better if the station just made a request when it is near empty.

The station's signals are as followed:
Supply/Request.
Station name: [Sulfuric Acid] Request %d
[Green Star] Fluid request 4 wagons
[Sulfuric Acid] Request 4 wagons, Minimum 4 wagons.

Hi. Yes, the liquids inside are considered fractional numbers, and the signals are integers.

There are several options for what to do:
1. Connect the dispatcher via the combinator: [ACID > 8] -> ACID.
2. Empty the tanks completely using pumps (sometimes this helps).
3. Make a request for 4 cars, minimum 2 (or 3.99).
4. Make a request for 8 cars and minimum 4.

In general, it seems that 4 cars of acid is a lot :)

I know 4 cars of acid is a lot but that's what I'm requesting. You want crazy overkill, my nuclear fuel production pulls 4 cars full of iron plate. But what I've done is design my entire network on 4 cars of everything everywhere. If i need more than 4 cars, I put up a second four car station.

So if I say a minimum if 3.9 cars, it'll go withdraw when there's 0.1 cars left? Will it still grab 4 entire cars or just 3.9?

In general, I would go the way of increasing free space at the station. I would make not 8 tanks, but, for example, 12. And I would request 6 cars with a minimum of 4.

And with a request of 4 and a minimum of 3.9, the train can carry 4 full cars, because upon arrival at the supply station, the train will adjust the delivery based on current data.