SPI-B 50K-B / 60K-B string inverter (sold as Chint SPI-B 50/60) Modbus register map

Notes

Source: Kehua Data "String PV Grid-tied Inverter - Monitor Protocol V2.0" (2021) - the vendor's own document, served by Chint Italy for the Chint-branded SPI-B 50/60 units it builds: https://chint.it/wp-content/uploads/product-docs/SPI-B-50_60/Istruzioni/SPI%20Monitor%20Protocol%20V2.0_005%20EN.pdf. §1.4.1 fixes the RS-485 framing: RTU, default 9600 bps (2400/4800/19200/38400/115200 selectable), no parity, 8 data bits, 1 stop bit; §1.4.2 gives the optional Ethernet port on TCP 502 with default IP 192.168.1.10, so the seed records the RS-485 path. Addressing is declared zero-based because the document's own example frame queries "address 4501" as PDU 0x1195 = 4501 (chapter 9). 16/32-bit values are big-endian, high byte and high word first, so word order stays HighFirst. The document states no factory slave address; the example uses 1 and the address-assignment chapter only describes the procedure. The unit 1 recorded here is therefore a placeholder, not a cited value, and the user must set their inverter's address on site. Function codes follow the document's own split: §2.1 input registers (FC 0x04, which holds the 4800 identity block and the 5000 PID-analog block; only the three 5000 rows are seeded) and §2.2 holding registers (FC 0x03, tables 2-1 and 2-2 with the 10000 identity block and the 11000 alarm/measurement block). Deliberate omissions: the 4800-4852 identity block of §2.1 (it is in the document but was not transcribed, so no row from it is claimed); the MPPT/PV string arrays (11064-11199); the manufacturer info, HMI and control-software version strings (10000-10069); alarm words 3-16 (11002-11015) and the alarm bit definitions, which the document tables by meaning rather than register; the PID/scheduling write block and the time-setting block; and the 4853-4872 PID-protocol variant block, which only applies to the PID option.