What is the connector called on the RS485 pins

1

I managed to lose the little connector that fits in the socket for the RS485 pins. What is it called? If someone has a part number I could toss into Digikey, even better. This is a Watchmon 4, so it’s the little 3 pin connector with the flathead terminals on it.

Thanks!

2

Hi aatheus,

Unfortunately we haven’t written firmware that uses the RS485 connector as CAN inverters have well and truly taken over the small-to-medium scale protocols.

Could you talk a little more about what you are trying to achieve with your WM4?

It’s a 3.5mm pitch Phoenix-style connector if that helps. A few manufacturers make these with small variations, so it might be a little tricky to get one that fits as well as your old one did from us (we buy them in batches of pairs)

Cheers,
James

3

I am trying to get the status and control the output of an Ampinvt charge controller. https://www.amazon.com/gp/product/B07SWVHLY2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

It’s got a pretty basic RS485 output

4

Hi Aatheus,

Unfortunately RS485 is just a communication standard, not a protocol. In other words, it defines the voltages and the way the devices are arranged electrically, but not what actually gets sent over the wires.

Without a protocol document (you can ask the manufacturer) we can’t really talk to it. We can still do safety stuff like balancing, monitoring or opening circuit breakers, but we won’t have as much control.

5

Indeed, I will inquire to see what they can provide. Based on https://icdn.ampinvt.com/2023/08/Wifi-Box.pdf they are talking Modbus over the RS485 port.

I would love to be able to tell the charge controller “stop charging” over the RS485 port, so that I don’t overvolt cells once they hit their cutoff voltage.

6

Hi aatheus

I’ve done something with a similar charger using Node-Red. Let me know if you’re interested and I can share details.
You will need the protocol document from the vendor though. Although they say it uses Modbus there are no standard commands and you’ll need the specifics for that vendor and even the specific model charger.
The im-wr4 seems to be a custom RS485-wifi adapter for the Ampinvt charger too. I use a generic Elfin EW11 that supports a few more connectivity options. (eg MQQT)

I found a communication protocol document for the Ampinvt online, but best to check with the manufacturer if that document applies to your charger.

Also have you seen this: GitHub - TripitakaBC/ampinvt_esphome: Esphome / Home Assistant solution for Ampinvt solar controllers
Looks like someone has already done a lot of the work!

Cheers,
Jon

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