I have a question regarding a scenario I found myself in, hoping that someone can clarify if the scenario I'm going to illustrate is possible (short premise: I'm a programmer, I'm not an electrician nor an electronic expert).
In my company we have 5 badge readers daisychained using RS485 and connected to an RS485 to ethernet adaptor which is connected to our LAN.
While working on renewing our server room the RS485 cable got cut by mistake by a tecnician of company A.
The day after, a tecnician from company B (the company that installed the badge readers and the software that collects the data) went to the office and said that the rs485 board on those 5 readers got burnt by a short-circuit caused by the cut cable while the devices were powered on. Since the readers now have to be changed, they suggested to move on ethernet ones.
Cutting the cable without being sure of it not being useful was certainly a mistake. However here's my thoughs: On one side company B may have exagerated the damage just to convince us to buy 5 new badge readers (I cannot know if they are actually burnt and I was not there when the tecnician came). On the other side I have company A that isn't keen to pay for 5 new badge readers for a damage that they think is impossible to be caused the way it was described.
I too, to be honest, find a short circuit surprising, but again I'm not an expert and In my programmer experience I've seen plenty of very unlikely things happen. I've also found on the internet different people burning their CIA chip on a C64 because of a cable unplugged while the machine was on, so to my unexperiend mind the short-circuit board-burning story may hold as well.
Of course I don't expect a black and white answer, rather I'd like to know similar experiences or an advice from someone that is experienced on this field.
Thanks in advance.