Well, it’s been a while since the last update so here it goes: we are preparing a few products which will be available in the shop, and as always the people that built them know them better. We’ll have a bit of a description of the manufacturing process going through all the required stages.
What will the products be?
Here it is : USB to RS485 adapter..
And the revised schematics:
Signal integrity test:
Cable: 30 meters of twisted pair subsea grade cable 120 ohm terminated
Driver: USB-RS485 Adapter with the 120 ohm terminator jumper ON.
The character ‘U’ (ASCII 0×55) sent via a terminal (PUTTY) with 8 bits data, 1 start bit, 1 stop no parity
The baud rate was set for 115200 bps, 50000bps, and 1Mbps, the waveforms were captured with a 1Gs/s digital storage scope triggered on the start bit.
Character ‘U’ was captured on the scope at the far end of the cable (30m)
The speed is 115200 bps
A detailed view of a bit at 115200 bps
This detailed bit view shows no sign of reflections on the falling and/or rising edges of the signal.
Finally the view of a 1Mbit/s signal over 30m of terminated cable.