User guide

Chapter 20
Math Instructions
20–4
Subtract SUB Output Instruction
(SUB)
SUB
SUBTRACT
Source A N7:0
879
Source B N7:1
2150
Dest N7:2
–1271
F1 F2 F3 F4 F5
ZOOM on SUB –(SUB)– 2.3.0.0.2
NAME: SUBTRACT
SOURCE A: N7:0 879
SOURCE B: N7:1 2150
DEST: N7:2 –1271
EDT_DAT
HHT Ladder Display:
HHT Zoom Display:
Ladder Diagrams and APS Displays:
(online monitor mode)
The value at source B is subtracted from the value at source A and then
stored in the destination.
Using Arithmetic Status Bits
C set if borrow is generated; otherwise reset
V set if underflow; otherwise reset. On underflow, the minor error flag
(S:5/0) is also set, and the value-32,768 or 32,767 will be placed in the
destination. Exception: If you are using a Series C or later SLC 5/02
processor and have the Math Overflow Selection Bit S:2/14 set, then the
unsigned, truncated overflow remains in the destination.
Z set if the result is zero; otherwise reset
S set if the result is negative; otherwise reset
Math Register
Contents unchanged.
Subtract (SUB)