I have an RS-485 input / output from a solar charge controller (SCC) and would like to read the output in two locations, while maintaining its input from one, or hopefully both of those locations (see pic below) everything will be contained within less than a metre square, so distances are not an issue:
Here's the setup – I have an Epever Tracer-BN solar charge controller in place and it has an RJ45 connector on the bottom, which gives data output and accepts some inputs to allow configuration and make read requests of the SSC. There is a proprietary bit of kit to display the output and allow me to change some setting on the SSC, but I would also like to be able to perform the same functions on a mobile app, so need to duplicate the signal to a Raspberry Pi.
The SSC only has one connector, and the supplied cable for that is an RS-485 with RJ45 connectors on it that looks like this:
I can connect to the Raspberry Pi using pins 3&5 or 4&6 into an adapter (link). Can I split the cable by connecting the remaining pair (4&6 or 3&5) into the proprietary monitor, or is this likely to cause problems, for instance because the signal will be… weaker? in some way broken?
I get that this is not a set of hardware that many people are probably intimately familiar with, but I am entirely unfamiliar with any of this stuff and I reckon that anyone who has a good working knowledge of the way these cables and information happens will be able to make a better judgement call / best guess than I can! I'm worried that there might be general problems associated with splitting a cable in the way I suggest.
I am particularly concerned because all the hardware I can find on the internet to do this apparently simple job is exorbitantly expensive, which makes me think that actually it is a very complex thing to do and I must be missing something. All the similar projects for specifically solar setups do not split the RS485 cable so again, I worry that there may be some reason why doing so is impossible.
Any thoughts or advice would be extremely welcome! The basic question I am asking is "do you think this will work, or do you foresee some potential problems I will encounter trying to split this cable?"
Best Answer
I wonder if you could try something like this ethernet splitter to split the signal, though as you say it will probably halve the output voltages, and depending on the requirements of your instruments that might cause issues. These cost ones of dollars, so you might as well give it a shot! Apologies if the proprietary monitor doesn't take a standard RJ-45 cable...