Waveshare RS485/CAN -- both RS485 and CAN at the same time?

[aren]

I have a Growatt 3000ES and a TianPower BMS from 2018. The Growatt will do either CAN or RS485, but CAN seems more widely supported with this project. The BMS only does RS485, from what I can find.

Will the Waveshare RS485/CAN do both RS485 and CAN at the same time? Or do I need to find a dual channel like the Seengreat?

[ai-republic]

Hi @aren,
the Waveshare RS485/CAN hat supports both protocols running at the same time. You have the RS485 A/B connections and CAN H/L connections. Just be sure that you connect the right pins to your inverter. You will need to cut a RJ45 cable for that and just use the specified wires (Pins) from the inverter manual to connect to CAN H and CAN L. If you need help just ask ;)

[ai-republic]

@aren I've implemented an initial Tian RS485/ModBus BMS binding. Once you're set up please test it with log level set to debug and inverter NONE and no plugins or optional services.
First let's see what you're getting. The specification is not really clear but shouldn't be a problem.

[aren]

I couldn't get the Waveshare RS485 serial port working, but I connected a USB RS485 that works on my Windows machine (so I know the wiring is correct). Here's the output I get from running start.sh

2024-10-20 14:31:26.281 | INFO  | Thread-2   | toinverter.core.Port:111   | Opening /dev/ttyUSB0 ...
2024-10-20 14:31:26.343 | INFO  | Thread-2   | toinverter.core.Port:113   | Opening port /dev/ttyUSB0 SUCCESSFUL
2024-10-20 14:31:26.346 | ERROR | Thread-2   | stoinverter.core.BMS:192   | Error requesting data!
java.nio.BufferUnderflowException: null
	at java.nio.Buffer.nextGetIndex(Buffer.java:721) ~[?:?]
	at java.nio.HeapByteBuffer.getInt(HeapByteBuffer.java:498) ~[?:?]
	at com.airepublic.bmstoinverter.protocol.modbus.J2ModMasterPort.sendFrame(J2ModMasterPort.java:113) ~[protocol-modbus-0.0.1-SNAPSHOT.jar:?]
	at com.airepublic.bmstoinverter.bms.tian.modbus.TianBmsModbusProcessor.sendMessage(TianBmsModbusProcessor.java:51) ~[bms-tian-modbus-0.0.1-SNAPSHOT.jar:?]
	at com.airepublic.bmstoinverter.bms.tian.modbus.TianBmsModbusProcessor.collectData(TianBmsModbusProcessor.java:43) ~[bms-tian-modbus-0.0.1-SNAPSHOT.jar:?]
	at com.airepublic.bmstoinverter.core.BMS.process(BMS.java:173) ~[core-api-0.0.1-SNAPSHOT.jar:?]
	at com.airepublic.bmstoinverter.BmsToInverter.lambda$start$2(BmsToInverter.java:269) ~[bms-to-inverter-main-0.0.1-SNAPSHOT.jar:?]
	at java.lang.Thread.run(Thread.java:1575) [?:?]
2024-10-20 14:31:27.365 | INFO  | Thread-2   | verter.BmsToInverter:268   | Reading BMS #2 TIAN_MODBUS on /dev/ttyUSB0...

[ai-republic]

Hi @aren,
will have to look into this. Thanks!

[aren]

Here's a simple communication I had with the BMS to query address number 1:

opening /dev/ttyUSB0 baudrate 9600

--- bytes sent:

01 04 10 00 00 17 b4 c4

--- response:

01 04 2e 14 df 03 03 20 54 00 d4 00 dc 00 00 00 00 1d 00 03 12 03 e8 29 16 00 06 27 10 0d 0d 0d 09 00 00 00 dc 00 d2 00 e6 00 00 15 e0 27 10 00 00 0d 50

[aren]

I tried to email you at the bms-to-inverter address listed in the source, but it bounced back.

I got it to work (mostly). Please see my diffs here:

main...aren:bms-to-inverter:fix_tianpower_bms

in readBatteryData, energyStorage.getBatteryPack(unitId) returns "null". I stopped debugging at that point b/c hopefully that's something straightforward to fix. Maybe a configuration issue? I'm not sure.

[ai-republic]

I fixed the error. Could you please do a Clean install with the Configurator app and test again?

[aren]

Still doesn't work for me. needs the changes in J2ModMasterPort.java

[ai-republic]

@aren I integrated your changes. Please do another Clean install :)

[aren]

Nice. Send/receive is working. readBatteryData() is not (this is where I stopped ... hope you have an easy fix!)

2024-10-22 00:03:46.263 | DEBUG | Thread-2   | o.ModbusRTUTransport:266   | Sent: 01 04 10 00 00 17 B4 C4
2024-10-22 00:03:46.342 | DEBUG | Thread-2   | o.ModbusRTUTransport:443   | Response: 01 04 2E 14 C2 00 00 29 16 00 DC 00 DC 00 00 00 00 1C 00 03 E8 03 E8 29 16 00 06 27 10 0C FB 0C F8 00 00 00 DC 00 DC 00 E6 00 00 15 E0 27 10 00 00 85 5F
2024-10-22 00:03:46.360 | ERROR | Thread-2   | stoinverter.core.BMS:192   | Error requesting data!
java.lang.IndexOutOfBoundsException: Index 1 out of bounds for length 0
	at jdk.internal.util.Preconditions.outOfBounds(Preconditions.java:100) ~[?:?]
	at jdk.internal.util.Preconditions.outOfBoundsCheckIndex(Preconditions.java:106) ~[?:?]
	at jdk.internal.util.Preconditions.checkIndex(Preconditions.java:302) ~[?:?]
	at java.util.Objects.checkIndex(Objects.java:365) ~[?:?]
	at java.util.ArrayList.get(ArrayList.java:428) ~[?:?]
	at com.airepublic.bmstoinverter.core.bms.data.EnergyStorage.getBatteryPack(EnergyStorage.java:49) ~[core-api-0.0.1-SNAPSHOT.jar:?]
	at com.airepublic.bmstoinverter.bms.tian.modbus.TianBmsModbusProcessor.readBatteryData(TianBmsModbusProcessor.java:60) ~[bms-tian-modbus-0.0.1-SNAPSHOT.jar:?]
	at com.airepublic.bmstoinverter.bms.tian.modbus.TianBmsModbusProcessor.sendMessage(TianBmsModbusProcessor.java:52) ~[bms-tian-modbus-0.0.1-SNAPSHOT.jar:?]
	at com.airepublic.bmstoinverter.bms.tian.modbus.TianBmsModbusProcessor.collectData(TianBmsModbusProcessor.java:43) ~[bms-tian-modbus-0.0.1-SNAPSHOT.jar:?]
	at com.airepublic.bmstoinverter.core.BMS.process(BMS.java:173) ~[core-api-0.0.1-SNAPSHOT.jar:?]
	at com.airepublic.bmstoinverter.BmsToInverter.lambda$start$2(BmsToInverter.java:269) ~[bms-to-inverter-main-0.0.1-SNAPSHOT.jar:?]
	at java.lang.Thread.run(Thread.java:1575) [?:?]

[ai-republic]

Great! Please do a Clean install again. I fixed the batterypack access for the ModBus BMSes.
You're apparently the first to test the ModBus implementation 😉

[aren]

Looks good! Thanks for your help on this. I was unable to get Growatt canbus working when I first tried, so that's next.

2024-10-22 09:24:44.259 | INFO  | Thread-5   | verter.BmsToInverter:294   | Sending to inverter NONE on can0...
2024-10-22 09:24:44.270 | INFO  | Thread-2   | verter.BmsToInverter:268   | Reading BMS #1 TIAN_MODBUS on /dev/ttyUSB0...
2024-10-22 09:24:44.320 | DEBUG | Thread-2   | o.ModbusRTUTransport:266   | Sent: 01 04 10 00 00 17 B4 C4
2024-10-22 09:24:44.405 | DEBUG | Thread-2   | o.ModbusRTUTransport:443   | Response: 01 04 2E 15 18 00 00 29 16 00 D2 00 DC 00 00 00 00 1C 00 03 E8 03 E8 29 16 00 06 27 10 0D 31 0D 2C 00 00 00 D2 00 D2 00 DC 00 00 15 E0 27 10 00 00 91 61
2024-10-22 09:24:44.405 | INFO  | Thread-2   | verter.BmsToInverter:320   |
BMS	SOC	  V  	  A  	 CellMinV 	 CellMaxV	CellDiff
#1	 100.0	54.0	0.0	3.372(#0) 	3.377(#0)	0.005

2024-10-22 09:24:44.406 | INFO  | Thread-2   | verter.BmsToInverter:390   | BMS alarms:
	NONE