connnect LCD display to Solar Charge Controller

[mills1983]

Hello, I'm new here an looking for some advice! I have a 100w folding solar panel which I use for charging a caravan battery. The last time I tried to use it, the LCD display (MT50) was not showing any info, and the battery was not getting a charge. A fellow caravaner helped me diagnose the problem - he thought that the panels were fine, but the charge was not going from the solar charge controller (LS1024BP PWM Solar Charge Controller). So I have bought a replacement solar charge controller, but the port on the back for connecting the LCD display (marked COM) has a different type of lead/connection to the original, and so I can't connect the LCD display. In the pictures you can see that LCD display is connected by a RS485 connection (looks like an ethernet cable) but the new one has set of 4 bare wires - presumably there is some kind of lead that this gets wired up to, but I can't find any info anywhere! Does anyone know what I'd need to connect the new Solar Charge Controller to the MT50 display unit? Thanks
! IMG_20171018_102732781.jpgIMG_20171018_102639400.jpg IMG_20171018_102645220 copy 2.jpg

[AzRoute66]

I downloaded the 'manual' from the website that I found thinking that the pinout would be there. Unfortunately the 'manual' I found is what most Americans would call a brochure and didn't have that info. What I did find is that this unit is definitely listed as 'positive ground' and the printing on the front of the unit seems to validate that. Not sure of the implications of that.

It does seem clear to me that you will need to crimp an RJ-45 connector to the four wires coming out of the hardwired COM port. I'm not sure which wire goes to which pin (isn't one of the four colors supposed to be blue???, not sure). Even if I was sure, I would still either find something definitive in the installation instructions or call the manufacturer.

Between the positive grounding, and my two 'not sures', and the fact that the cable seems to be hardwired, I think I would return it if possible and get something more 'plug and play' with an MT-50.

As usual, someone here will have seen this before and come in with a quick and dirty answer if you are patient enough to wait for it.

Edit: I did find another manual that indicates that the COM cable should be terminated with an RS485 waterproof connector, not four bare wires. Then, they suggest an RS485 to USB cable to allow monitoring with software on a PC or mobile device. At no time do they attempt to address a MT-50 device. Doesn't mean that it can't be done, or even that it might not be easy, just that they are not going to make it real easy.

[sensij]

Here is the product page

http://www.epsolarpv.com/en/index.php/Product/pro_content/id/773/am_id/136

And here is the manual (includes a pinout for a 4 pin waterproof connector, which you seem to be missing):

http://www.epsolarpv.com/en/uploads/news/201608/1471339278298743.pdf

If I had to guess:
red = Vcc (should be verifiable with a meter)
black = GND
white + yellow = A+B

I would also guess that if you get power and ground correct, the LCD will at least light up, and then it is just a matter of swapping A and B until it communicates correctly.

The MT50 manual has a pinout diagram too, although pay attention to the weird numbering.

http://www.epsolarpv.com/en/uploads/news/201506/1433818814375560.pdf