As a working electronics engineer, I would agree with Sven that these two terms are NOT exactly synonymous, and would disagree with those who suggest the terms are entirel interchangeable.

In most technical contexts, I would advise the use of 'flashing' as the more formal term, 'blinking' sounding somewhat more colloquial.

But in this particular sort of technical application, I believe there IS a distinct nuance of meaning, and sometimes you will need to use one or the other word to make the distinction clear. As Sven has said in more erudite terms, 'flash' usually implies something that is normally OFF, but comes on for a brief period; for example 'give me a signal by flashing your torch once when you are ready'

'Blink', on the other hand, suggests something that is normally ON, but goes out for a short period (think of blinking your eyes...). A more formal word for this is 'occulting'

In some electronics instances, an indicator that is normally steadily lit may 'blink', to indicate the passage of data, for example.

Where there is no difference in on and off times [i.e. a 50% duty cycle or 1:1 mark/space ratio], there is clearly no distinction to be made, and in this case, I would personally stick to 'flashing'.

As a footnote, do please note that this discussion has already taken place at some length in this forum, and should be in the KOG (somewhere!)