Mitsubishi FX2N Double Word 32Bit Query??

[504bloke]

Hi

I have read the manual and cannot find my answer.

I will be using a Double Word 32Bit Unsigned format to give me

0 - 2,147,483,648 in day D0000

Now if i needed a signed version the MSB of D0001 would be the sign bit 0=Pos 1=Neg

Is there a bit i need to set to tell the fx i will be using the register as Signed or Unsigned ?

 

[Sergei Troizky]

Unsigned for PLC means that the most significant bit is used not as sign but as value. This doubles the maximum value that may be represented, for 32-bit to 4294967295.
Unsigned values may be used in some PLC brands for timer/counter presets and comparisons.
For calculations the format is usually considered signed.
In Mitsubishi all values are signed and 32-bit can represent values from -2147483648 to +2147483647.
They may be though declared and indicated unsigned in the HMI.