Disappearing Key Assignments

[ijabbott]

(01-02-2020 03:55 PM)cdmackay Wrote:  

(12-30-2019 07:56 PM)Sylvain Cote Wrote:  [*]DB9F-to-DB9M RS-232 LED Tester

please forgive me going off-topic a little, but can you explain what the two sets of 8 LEDs denote, on the tester?

Is the left set of 8 looking in one direction, the right set in the other?

Each pair of LEDs should indicate the state of the corresponding signal with respect to signal ground. One LED should light when the signal is positive (logic 0) and the other should light when the signal is negative (logic 1). Some testers replace the pair of LEDs with a 2-pin, bi-colour LED. The pair of LEDs is connected in parallel with opposite polarity, so at most one of them should light up.