Arno Uhlmann

Dear system32, the ModBusSN index is set to 01, the inverter is defined as "slave" and not in parallel. Thank you for your link to the property menu, the ModBus settings are well hidden. But there is still no response to my small 8 bytes request. I tested the signal just to the RJ45 plug sitting inside the inverter. I am using 9600,8N1 with my atmel ATMega324 and my RS485 circuit works fine together with our Lumel power meter. If there is nothing else to check, I will try to do it with your Python script ... Thank you for your support, Arno

Dear system32, a very big thank you for your support ! You are the first I met, who could help me with my basic RS485 problem. I understand your source code and I tried your example ( write 0x01, 0x03, 0x00, 0xb6, 0x00, 0x03, 0xe4, 0x2d) but my Sunsynk 8k did not reply any thing. I used 9600baude, 8N1, the ModBuus SN is 01. I am using Pin 1 and Pin 2 of the RJ45 plug. I even have an osciloscope and can see the outgoing code on the RS485 A/B lines. Is there any special timing I have to do? How long do I have to wait for an answer? Is any initialisation necessary? Thank you a lot ! Arno

Dear *, for my Sunsynk 8k inverter I am looking for a RS485 Modbus connection for my data logger. I only need the pure data, no charts or user interface. So I need the absolute basic bytes to send a read request 0x03 via RS485. I am using an Atmel chip, programmed with C++. No windows, no raspberry, no USB. I allready knoow the pinning of the RJ45, I set the ModBus address to 01 and I know too, the speed 9600bps, 8N1. What is the absolute minimum string to get an answer: byte[0] = 0x01 = address index of the meter byte[1] = 0x03 = function "read" byte[2+3] 0x00 0x01 = read parameter #17 byte[5] = 0x04 = read 4 bytes byte[6+7] = crc16 MODBUS Just one valid bytes string would help ! Thank you for any hint, Arno

Dear *, for my Sunsynk 8k inverter I am looking for a RS485 Modbus connection for my data logger. I only need the pure data, no charts or user interface. So I need the absolute basic bytes to send a read request 0x03 via RS485. I am using an Atmel chip, programmed with C++. No windows, no raspberry, no USB. I allready knoow the pinning of the RJ45, I set the ModBus address to 01 and I know too, the speed 9600bps, 8N1. What is the absolute minimum string to get an answer: byte[0] = 0x01 = address index of the meter byte[1] = 0x03 = function "read" byte[2+3] 0x00 0x01 = read parameter #17 byte[5] = 0x04 = read 4 bytes byte[6+7] = crc16 MODBUS Just one valid bytes string woulds help ! Thank you for any hint, Arno