I was tinkering around in the timing shack last weekend, knocking off some of the odd jobs I never seem to have time to attend to. One of them was to package up a set of RS 232-485 converters to use for sending data to a D Line display over a longer distance, as we have an extensive buried cable network and an off-course timing room that can potentially be hundreds of metres from the finish line.
I got the three largest spools of drop line that we own and linked them together to form a cable 350 m long, then plugged in the D Line without any converters. Sent it some test data from Split Second without issue. Then I used two more pairs in the drop line to add another 700 m of cable length - wanted to see where the unconverted signal would fail to be received. At 1050 m, no problem.
I connected in the fourth and fifth pairs in the drop cable to make a total length of 1750 metres, and the signal still made it to the display in unconverted RS 232. Impressive how well this old standard works when there is only one-way data transmission. I should note this data was being sent directly from a physical serial port. I did box up the 485 converters so they're all tidy now, but not sure if I'll use them now.
Anyone else been using this time to tidy up some the 'to do' list?