FX Series Programmable Controlers Applied Instructions 5
5-50
Points to Note:
a) When floatin
point numbers are used the zero, borrow and carr
fla
s (M8020, M8021 and
M8022 respectivel
) operate at the followin
times; M8020, Zero: is activated when the
result is Zero.
M8021, Borrow: is activated when the result is smaller than the smallest possible number.
The result is forced to equal the smallest number and the associated fla
is set ON.
M8022, Carr
: is activated when the result is lar
er than the lar
est possible number. The
result is forced to equal the lar
est number and the associated fla
is set ON.
b) Floatin
point numbers alwa
s
occup
32 consecutive bits, i.e. 2
consecutive data re
isters. When
convertin
between float and
decimal numbers please al-low
enou
h destination devices, i.e.
Instruction
Double word
operation
Status of
M8023
Number of
source
registers (S)
Number of
destination
registers (D)
Remark
FLT
NO
OFF 1 (S)
2 (D, D
+1
)
Convert to floatin
point
FLT (INT) ON
2 (S, S
+1
)
1 (D) Convert to decimal
DFLT
YES
OFF
2 (S, S
+1
) 2 (D, D
+1
)
Convert to floatin
point
DFLT
(DINT)
ON
2 (S, S
+1
) 2 (D, D
+1
)
Convert to decimal
Zero M8020
Infinit
Positive Value
Borrow
M8021
Carr
M8022
Ne
ative Value
Ver
small
Carr
M8022
Infinit
General note:
For more information about float and scientific notations please see Chapter 4, Advanced
Devices, pa
e 4-46
