Lumel N31U User Manual

Also see for N31U: Quick start guide Service manual

29N31U User manual5.5.3 Implemented functions of MODBUS protocolThe following functions of the MODBUS protocol have been implemented inthe N31U meters:• 03 (03h) – readout of registers group.• 04 (04h) – readout of input registers group.• 06 (06h) – single register writing.• 16 (10h) – registers group writing.• 17 (11h) – slave device identification.5.5.4 Map of the registersThe register map of the N31U meter is divided into separate groups of 16-bitor 32-bit registers. Data stored in 32-bit registers are additionally available inthe format of 16-bit registers, with the value of one 32-bit register is stored intwo 16-bit registers.The 32-bit registers store data in the float format compliant with IEEE-754.Bytes sequence: B3 B2 B1 B0 – the oldest byte is transmitted as the first. The16-bit registers representing 32-bit values in two successive registers havebeen doubled in another address space with a byte sequence: B1 B0 B3 B2.The table below shows the register map of the N31U meter. The addresses in thetable are the physical addresses. The register number should be increased by 1when using the programs where the addresses are provided in a logical format.Address range Value type Description4000 – 4024 16 bits Readout and write registers - configuration registers4200 – 4219 16 bits Readout only registers with system parameter values7500 – 7515 32 bits (float) Readout only registers with measuring and calculated values.7600 – 7668 32 bits (float) Readout and write registers - registers with configuration data.7000 – 7030 16 bits Readout only registers. Registers store the same data as the registers 7500-7514, whereone value is stored in two successive registers.7200 - 7335 16 bits Readout and write registers. Registers store the same data as the registers 7600-7668,where one value is stored in two successive registers.