Low cost 485 adapter for your computer

[Dave Loucks]

Modern computers are no longer supplied with serial ports (other than Ethernet and USB), and even back when they did they were supplied, they were RS-232.  Even then to get an RS-485 connection, you'll need a converter.

There are ton of high quality converters from companies like B&B Electronics, but if all you want is an inexpensive 2-wire USB to RS-485 converter, this one has been tested and works fine with the VBA_COMMS program.

Don't expect it to withstand the rigors of an industrial environment, but if you are looking for a low cost way of programming the Modbus MINT, this is a great choice (at least in February 2018 when this article was written).




Here's a wiring diagram showing how the JBTech USB to RS485 adapter would be wired to the Modbus MINT (mMINT).  Note that I used electrical tape to secure the cable to the USB adapter.  The screw terminal landing on the USB adapter is not very robust.