MB_SERVER "ILLEGAL DATA ADRESS"

Hello,

I don't see how long your DB5 is defined and how constructed with full structure. Be careful here, with Client request your 120 address can be different to exact expected 'register' address because your structure is defined differently. Also I see there Float data type which takes two registers and in case you want read register 120 and 80 registers as count, with FLOAT data type it can be huge data area. Pls try to do simple math and count carefully with register type as mandatory and amount of registers to read. How much registers generally you can poll is described somewhere with Modbus problematic, also inside help Online to blocks or system manual.

Just one tip, your DB5 need have unchecked Optimized access option (disabled).