Hello. I always wanted a method to read the count of rocket parts from a silo. That's the more interesting part of this mod to me than controlling the silo. But there's a problem: you read rocket parts to the rocket part signal. That signal is hidden, so I can't set a combinator to use it (say input in an arithmetic combinator) without cheating. Could you perhaps change the mod to output the count in a different signal, possibly a new non-hidden signal that this mod adds?

Attach a wire to the combinator to get the signals

In this screen shot you can see that 4x rocket parts have been made .. https://i.imgur.com/dzZli91.jpeg

Yes, I know I can connect a wire to the combinator in the lower right corner of the silo to read the signals, and that it reads the number of rocket parts. But I want to set a decider combinator to send a signal if there are at least 50 rocket parts. I can't do this easily, because the signal type that is used is hidden, which means the UI does not allow me to select it in the configuration of a decider combinator. It's still possible to access the number of rocket parts in a roundabout way, by masking out all the other signals (the ones for rocket fuel, LDS, RCU) and then accessing the remaining ones, but it should have to be that complicated.

Not directly the same question, but I'd like to also get a different signal when the silo is ready to launch the rocket, or perhaps just see a signal with 100 rocket parts then.

@b_jonas, if having a synchronized rocket launch (multiple rockets at the same time) is what you want, you don't need that signal...
All you need is two decider combinators and 1 arithmetic thingy. The following example shows the idea for 9 synchronized rockets which all launch satellites:
Combinator 1: (if "satelites" >= 9: send 1 signal to "Rocket Icon") -> Send it back to the rockets circuit
Combinator 2: (if "satelites" < 9: send 1 signal to "P Signal") -> Send this to the arithmetic thingy
Arithmetic: (Execute "P Signal" * (-1) ) -> Send it back to the rockets circuit

Connect all your rockets together and you should be good to go.
This works because satellites will show on the circuit network if they are inside the rocket payload.

edit: added the missing arithmetic for the example...