Mitsubishi Digital Electronics FX0S Manual

A SERVICE OF

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FX Series Programmable Controlers Applied Instructions 5

5-26

Operation 2:

(Applicable units: FX

(2C)

)

This function is equivalent to FNC 120 EADD.

When ‘floatin

g

point mode fla

g

’ M8023 is active, i.e.

ON, DADD and DADDP instructions can be used to

perform floatin

g

point additions.

When M8023 is reset, i.e. OFF floatin

g

point

manipulation will not occur. Constants (K/H) and

floatin

g

point numbers (stored in double data

re

g

isters D) can be added in an

y

confi

g

uration. The

constants (K/H) will automaticall

y

be converted to the ‘floatin

g

point format’ for the addition

operation. Answers for an operation can onl

y

be stored in double (32 bit) data re

g

isters. Items a)

and b) above are also valid for this operatin

g

mode.

FX2N Support for floating point operations

5.3.2 SUB (FNC 21)

Operation 1:

(Applicable to all units)

The data contained within the source device, S

2

is

subtracted from the contents of source device S

1

.

The result or remainder of this calculation is stored

in the destination device D. Note: the ‘Points to note’, under the ADD instruction (previous

pa

g

e) can also be similarl

y

applied to the subtract instruction.

Operation 2:

(Applicable units: FX

(2C)

) This function is equivalent to FNC 121 ESUB. The

information re

g

ardin

g

‘Operation2:’ of the ADD instruction appl

y

similarl

y

to this second

operation of the SUB instruction (with the exception of a subtraction bein

g

performed instead

of an addition). A

g

ain, onl

y

constants and double data words can be manipulated with onl

y

DSUB, DSUBP instruction formats bein

g

valid.

Mnemonic Function

Operands

Program steps

S

1

S

2

D

SUB

FNC 21

(Subtract)

One source

device

is subtracted from

the other - the

result is stored in

the destination

device

K, H, KnX, KnY, KnM, KnS,

T, C, D, V, Z

KnY, KnM, KnS,

T, C, D, V, Z

SUB, SUBP:

7steps

DSUB,

DSUBP:

13 steps

When usin

g

M8023 to subtract floatin

g

point

data, onl

y

double word (32 bit) data re

g

isters

(D) or constants (K/H) ma

y

be used. See pa

g

e

4-46 for more details re

g

ardin

g

floatin

g

point

format.

X10

M8023

M8000

M8023

H3F D 4

[ S1 ] [ D ]

D 4

[ S2 ]

DADDP

Note

: The use of M8023 is not supported in FX

2N

units.

The appropriate dedicated floatin

g

point instruction should be used instead E.

g

. Instead of

DADD with M8023 ON, use FNC 120, DEADD.

- See section 5.11

X0

SUB D 10 D 12

[ S1 ] [ D ]

D 14

[ S2 ]