Delta Electronics Programmable Logic Controller DVP-PLC - Manual (Page 434)

8 Application Instructions API 100-149
DVP-PLC Application Manual 8-32
API Mnemonic Operands Function
121 D ESUB P Floating Point Subtraction
Controllers
ES/EX/SS SA/SX/SC EH/SV
Bit Devices Word Devices Program Steps Type
OP X Y M S K H KnX KnY KnM KnS T C D E F
S
1
* * *
S
2
* * *
D *
DESUB, DESUBP: 13 steps
PULSE 16-bit 32-bit
ES EX SS SA SX SC EH SV ES EX SS SA SX SC EH SV ES EX SS SA SX SC EH SV
Operands:
S
1
: Minuend S
2
: Subtrahend D: Remainder
Explanations:
1. See the specifications of each model for their range of use.
2. Flags: M1020 (zero flag); M1021 (borrow flag); M1022 (carry flag)
3. S
1
− S
2
= D. The floating point value in the register designated by S
2
is subtracted from the floating point value
in the register assigned by S
1
and the result is stored in the register designated by D. The subtraction is
conducted in binary floating point system.
4. If S
1
or S
2
is an designated constant K or H, the instruction will convert the constant into a binary floating point
value before the operation.
5. S
1
and S
2
can designate the same register. In this case, if the “continuous execution” instruction is in use,
during the period when the criteria contact in On, the register will be subtracted once in every scan by pulse
execution instruction DESUBP.
6. If the absolute value of the result ＞ maximum floating point available, the carry flag M1022 = On.
7. If the absolute value of the result ＜ minimum floating point available, the borrow flag M1021 = On.
8. If the result = 0, the zero flag M1020 = On.
Program Example 1:
When X0 = On, binary floating point (D1, D0) － binary floating point (D3, D2) and the result is stored in (D11, D10).
D0 DESUB
X0
D2 D10
Program Example 2:
When X2 = On, K1234 (automatically converted into binary floating point) － binary floating point (D1, D0) and the
result is stored in (D11, D10).
K1234 DESUB
X2
D0 D10
Remarks:
For floating point operations, see “5.3 Handling of Numeric Values”.