Hi Rovert. I just came across comments you made last year regarding Raymarine ST1000/2000 tiller pilots, so sorry to be so late replying. You enquired about ram position measuring, and well, there is no such thing in the ST1000/2000. They just run the drive one way or the other and the control board has no feedback of the ram position. That's why they just bottom out and grind away to destruction if you let them. The Simrad TP's have rotation detection (which they use for stall detection), and the latest models also use this for "rudder feedback" which means the rotation sensors provide feedback so the control board knows where the ram is.
I fitted limit switches to my ST2000+ and it has performed faultlessly ever since.