Hi to all,

I'm facing a little problem that i couldn't figure out whats the problem. attached some screen shots!.

I'm reading the density value as shown in Flow.jpg into %MW100(2 registers) this far everything OK(the value is Float and not swapped), and other modbus master will read it from my list in PLC but here starts a problem. if i leave the density value in %MD100(%MW100 - LSW and %MW101 - MSW) the values are not readable and not representing any thing.

So i swapping the %MW100 and %MW101 as shown in PLC.jpg, in this case the values that i read are more relevant but still having a problem as shown the difference between modbus.jpg and modbus2.jpg.

Im using CM1241 485 module.

I made the simulation with modbus slave and modscan software.

any ideas would be great.

Thanks in advance.

At this moment i payed attention for the phenomenon shown in attached file.

any ideas why the data changed? i don't use this registers except for data swapping...

Estring

At this moment i payed attention for the phenomenon shown in attached file.

any ideas why the data changed? i don't use this registers except for data swapping...

 please explain it: what is the Tag_3? DWord has not decimal.

Thanks,

the issue that i read from the modbus register by register and the Density value is a floating point value, so i thought if i save each register in specified memory word and convert it from Dword to Real it would be ok.

In the end i just made a move function for each register and reading it in the same way Floating point.

also i've tried to understand how does Dword and Real types represented in modbus...

Thank for all.