Measurement Registers V3 (M550/M560/M570 3X and duplicated 3X)

Internally, the M550/M560/M570 3X registers are duplicated in the 4X register area from address 42001, (internal register offset 2000 (07D0h)).
This allows PLCs that can’t read floating point data in the 3X area to retrieve the measurements from the 4X area.

The registers are listed with their Modbus addresses.
The data held at these addresses are Read-Only.
3X registers are read using function 04h.
4X registers are read using function 03h.

A sample read packet using code 4 to access the 3X registers will look like this:-
[Node][04][start address][No. of Double Registers Requested][CRC(2 bytes)]
e.g. To read line to neutral voltages on node 23h:-
[23h][04h][0006h][0006h(3, 4 byte regs)] [CRC(2 bytes)]
The node’s return packet will look like:-
[23h][04h][0Ch][12 bytes of data = 3 floating point numbers] [CRC(2 bytes)]

A sample read packet using code 3 to access the 4X registers will look like this:-
[Node][03][start address][No. of Double Registers Requested][CRC(2 bytes)]
e.g. To read line to line voltages on node 23h using the duplicated measurements in the 4X area:-
[23h][03h][07D0h][0006h(3, 4 byte regs)] [CRC(2 bytes)]
The node’s return packet will look like:-
[23h][03h][0Ch][12 bytes of data = 3 floating point numbers] [CRC(2 bytes)]

The list below is the default order of the 3X registers in the M550, M560 and M570.
The order can be altered using the MultiView V6 program, supplied on request or downloaded from our website, or by a suitable SCADA program.

Sample Coding