How Fly-by-wire throttle systems work!

This is an attempt to simplify the new tech that was earlier seen only in bigger and more expensive bikes and with the launch of the new KTM 390, we would seeing this electronic throttle mechanism too.

We were discussing the change from cable driven throttle to the newer optical sensor /fly by wire systems which were noticed en masse on the Triumph Tiger and now we find that the KTM 390 too will have it. A completely new segment of riders will be shortly introduced to this technology, probably just one of many new things to come to India soon.

Indian riders born and brought up with the constant fear of substandard cables and the like, always had questions and even figured out which Yamaha or Pulsar cables for their Harleys.
Now with the advent of the Optical Sensor (or throttle position sensor) driven throttles, the fear of dust, rain and physical damage continue in the mind of the riders.
I have tried to explain how the new system is built with a certain 'vision' and thought and how this works.

The signal from the throttle control actuates a transponder which generates electrical impulses. This is almost similar to the volume button on an older amplifier that can be found in almost any house. Depending on the twist, the the signal that goes to Electronic Control Unit (ECU) of your bike is varied. The ECU calculates th demand and the urgency (rate of change as seen by the OS/TPS and therefore commands the throttle butterflies to open at a given computed rate.
This involvement of the ECU then permits a few things to be managed very well- cruise control, variable power  requirements like rain, of road, track etc. Any yank on the throttle when in off road-situation would instantly result in a more relaxed command to the thrttle body than what its cable driven counter part would- possibly resulting in an unwanted jerk, which could result in wheel spin and therefore a crash too.
This is the good of the 'fly by wire' till such time that the desi mentality of 'what if..' creeps in? What if dust enters the optical sensor or the resistor (depending on the bike) which is generating the throttle position reading, and the unthinkable happens. 500Km from home and possibly 700 from the nearest service center!
Let me try and explain how the system is integrated in the Triumph Tiger and how redundancy is built in.
The optical sensor (OS) that works with the throttle, has a secondary sensor with it. In the failure of the first sensor and when the ECU detects the lack of a signal from OS1, the OS2 takes over and the motorcycle can carry on till its destination and then service center for repairs.
The cynical rider came up almost immediately with plausible events on Indian roads- fall- unintentional in a parking lot, crash, or an errant stone from under the tire of another vehicle- ten different scenarios. We agree to one scenario- and proceed. So the motorcycle has a fall or is physically damaged and in the unlikely event of both OS'es getting damaged, then what?

Should the ECU detect failure of both the OS it sends an emergency override signal to the engine, and will lock the throttle at 3000 RPM constant. This enables the bike to get itself home in a 'limp home' mode and the 3000 RPM is enough for the bike to maintain a steady and relatively safe 60kmph in 6th gear- enabling it to ride on almost any highway in the world.

IF one puts logic to it, then it suddenly seems very simple. It would be interesting to learn from others on topics that are new to our sub-continent- also where my knowledge or writing may be incomplete, please do feel free to pen in your comments.