# Mitsubishi Electric Q172CPU Programming Manual Page 288

Melsecq series motion controller sv43.

7 MOTION PROGRAMS FOR POSITIONING CONTROL
(c) How to handle variable as 64-bit double precision real number
By handling a variable as a 64-bit double precision real number, arithmetic
operation spanning multiple blocks can be performed without reduction in
precision.
Describe a capital letter ":F" after a #n variable.
#nF : Four variables of #n to #n+3 are used and handled as a 64-bit double
precision real number.
63
#n+3
The data format of a 64-bit double precision real number conforms to the
binary floating-point type double precision (64 bits) of IEEE Standard.
63
51
Bits 52 to 62: Exponent part
Bit 63: Sign part
[Example]
#@10:F=#@20:L/#@22:L;
The division result of 32-bit integers, [#@21, #@20] and [#@23,
#@22], is stored to a 64-bit real number, [#@13, #@12, #@11,
#@10].
#@10:F=#@20:L;
A 32-bit integer, [#@21, #@20], is expanded in sign to a 64-bit
real number, [#@13, #@12, #@11, #@10].
#@40:L=#@30:F;
A 64-bit integer, [#@33, #@32, #@31, #@30], is expanded in
sign to a 32-bit integer, [#@41, #@40].
<Restrictions>
64-bit double precision real numbers cannot be used in the function INT
and FTL.
(5) Assignment of variable
When a decimal point is added for assignment of a value to a variable, the value
is assigned as shown below.
#@10:L=1.;
¨10000 enters in #@10, #@11.
#@10:F=1.;
¨10000 (64-bit double precision real number) enters in #@10,
#@11, #@12, #@13.
"1." is converted into a value of four decimal places.
(Converted to a value of four decimal places regardless of the unit (mm,
inch, degree).)
31
#n+2
#n+1
31
Bits 0 to 51: Significant digit part
7 - 27
Bit 0
#n
Bit 0

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