When I was playing around with the scanner (to find out the correct baud rates & RS485 adresses), I also had received sporadically data/response from the TWC3, but it was no proper MODBUS RTU response, which could lead to any further progress.
I assume, that any device, which wants to communicate with the TWC3, has got to initiate a special “handshaking” and/or “certificate exchange” and/or has got to send “permanent keep alive data”. This is also my conclusion after I scrolled through the Neurio documentation.
By-the-way: Meanwhile, I was able to reach EMEA TWC support. When I asked for documentation (and told them, that it seems, that it works with the Neurio device), they simply adviced me to buy the Neurio device. So for me, it seems, that they are not willing to disclose the TWC3 RS485 mechanism at all.
I see. My understanding was that we got no data at all, so obviously you can understand my excitement at seeing data yesterday, even if I didn’t understand it.
Would reverse engineering the firmware be an option?
I have a TWC3 connected to Neurio W2 for dynamic power management. It works fine. I tried capturing some data from the RS485 line but I can’t figure out how to interpret it.
It appears a message is sent every second.
I watched the values update every 2s in Tesla One app. Neurio W2 has 4 ports for the CT clamps and I can see all 4 values in the app. Precision is 3 digits after the decimal. (e.g. 105.832W).
CT1: 105W
CT2: 270W
CT3 and CT4 fluctuate between approximately -0.063W and 0.063W. Negative value the app shows as “export”.
Here’s a few messages I saw at the same time as I saw the above mentioned values in the app. Maybe someone will have an idea how to interpret these messages?
I’ve tried reading through all of this thread, and just thought I’d ask here again - even though it seems it has been asked before…
If you have two of these and they are configured for power sharing, there is no way to see the output of the second unit in the Tesla Integration, correct? Any known ways to deal with this?
"The device talks RS-485 modbus RTU at 115200,8,1.
unfortunately don’t know what the modbus register map is but am putting together
some stuff to make good traces of the communication to the Universal Wall Connector.
I looked at it on a scope and the Wall connector polls every second and the Neurio
responds. The serial decode said the RTU request was read 10 holding registers at
address 0x88 and the sensor responds back with 20 bytes of payload,
which I don’t know the meaning of yet. "
Can you try logging data after switching to baudrate 115200 ?
if that summary is correct, then converting the binary to hex , I would expect to see the address 0x88 there, which I do, the next hex should be the function code afaik, which in the binary given is 0xA7 which doesn’t seem to be a standard modbus code, it would be 0x03 for reading registers for example. I can only assume the binary isn’t correct. depending on your setup, it might be worth trying qmodbus to decode directly from the serial …
I must declare that I don’t have a lot of modbus experiance, and my other charger is a ‘wallbox pulsar plus’ which uses modbus RTU to talk to an energy meter , and that energy meter is a special revision just for wallbox. the wallbox also enrolls the meter in a fashion similar to what the TWC3 seems to do too