Another Binary Question...

[mks57]

@pikolo77

Another fun aspect to this is simple signaling. All data transmission (except for quantum and optical) is predicated on one system setting a voltage level on a wire and another system reading that voltage level. It is absolutely possible to rig a system where a single wire could have 2, 4, 8… different discrete voltage levels going across it to take the place of 3 lines or three seperate sequential signals to represent those 8 possible values. But signaling from one state to another (say a 0 to an 7) could electrically be very difficult without accidentally triggering an intermediate state (say a 2). Most electrical devices have a built in capacitance that makes them hold and dissipate electrical charge over a period of time rather than being at one voltage and then instantaneously at another. The larger the spread (i.e. the more discrete states one signal can have), the more likely it would be prone to those kinds of errors.

I wonder what James Burke of Connections would have to say about this.

Some old telemetry systems use PAM (pulse amplitude modulation) to transmit data values. The receiving system uses an ADC (analog to digital convertor) to measure the voltage in the center of the parameter’s time slot. Each frame of data includes 0% and 100% calibration pulses to allow the receiver to automatically compensate for drift in gain and DC offset.