The wave form below is a Ford smart charge alternator system.
It shows the start of the engine, where the current goes off the scale, followed by the activity which stabilises the charging system.
I have used a graph channel to represent each of the digital signals.
The following wave form shows a close up view of the above image.
This shows the digital signals in detail.
The wave form below is that of the vehicle battery, under start up conditions, and the main ground to engine, volt drop. The sample is from a 306 petrol engine car, that was suffering some poor running issues. This is one of the first checks I like to make, before getting too involved.
The Red wave represents the battery and the Blue represents the main ground.
This wave form is that of the same car, as above, with a new battery negative cable fitted. This action allowed a positive intialisation of the engine ECU and a solution to the running faults.