KEYENCE Visual KV Series - Manual (Page 177)

2.4 Instruction Details
1
2
3-153 Chapter 2 Instructions
SUB (Subtraction)
Coding
Description
• The SUB instruction subtracts the operand value from the contents of the internal
register and inputs the result back into the internal register.
• In the above example, "#00100" is subtracted from the contents of DM0000 and
the result is stored in DM0001.
• When the contents of DM0000 is "#00150", for example, "#00050" is stored in
DM0001.
DM0000 (#00150) – #00100
➞ DM0001 (#00050)
Note 1: When the operation result is a negative value (-), the 2's complement value
is also stored in the internal register.
Special utility relay 2009 turns ON.
Note 2: To convert the complement into an antilogarithm, add the following opera-
tion:
Inverted bit of complement + 1 = Antilogarithm
Tips
Solution when operation result is a negative value
When DM0000 is "#10" and DM0001 is "#30", "#20" is stored in DM0003.
Arithmetic flag
2009 Turns ON when the result of a SUB operation is negative. Turns OFF at
other times.
2010 Turns ON when the contents of the internal register is "0" after a SUB
operation. Turns OFF at other times.
2011 Turns ON when the result of a SUB operation is positive. Turns OFF at other
times.
2012 The DM or relay indirectly addressed with #TM is out of range.
➮ "Indirect addressing" (p. 3-127)
DM0000
LDA
#00100
SUB
DM0001
STA
2002
Line No. Instruction Operand
0000 LD 2002
0001 LDA DM0000
0002 CON
0003 SUB #00100
0004 CON
0005 STA DM0001
0
1
= $0001 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1
1 - = $FFFF 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
0 = $0002 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0
2009
2's complement is stored.
Internal register
Operand
Underflow
DM0000
LDA
DM0001
SUB
DM0002
STA
COM
#0001
ADD
DM0003
STA
2002 2009
2009
DM0000 - DM0001 =
(Stores positive value)
(Stores negative value)
Absolute value
is stored.
Positive value DM0002
Negative value DM0003
SUB / @SUB
KVNKA Chap 02_4cP.p65 08.3.11, 0:02 PM 153