Delta DVP-ES2 - Manual (Page 138)

D V P - E S 2 / S A 2 / S S 2 / S A2 / S X 2 / S E O p e r a t i o n M a n u a l - P r o g r a m m i n g
3 - 2 2
The decimal floating point is represented by 2 continuous registers. The register of smaller
number is for the constant while the register of bigger number is for the exponent.
Example: Store a decimal floating point in registers (D1, D0)
Decimal floating point = [constant D0] × 10
[exponent D1 ]
Constant D0 = ±1,000 ~ ±9,999
Exponent D1 = -41 ~ +35
The constant 100 does not exist in D0 because 100 is represented as 1,000 × 10 -1 . The range of
decimal floating point is ±1175 Ч 10
-41
~ ±3402Ч10
+35
.
The decimal floating point can be used in the following instructions:
D EBCD: Convert binary floating point to decimal floating point
D EBIN: Convert decimal floating point to binary floating point
Zero flag (M1020), borrow flag (M1021), carry flag (M1022) and the floating point operation
instruction
Zero flag: M1020 = On if the operational result is “0”.
Borrow flag: M1021 = On if the operational result exceeds the minimum unit.
Carry flag: M1022 = On if the absolute value of the operational result exceeds the range of use.
Index register E, F
The index registers are 16-bit registers. There are 16 devices including E0 ~ E7 and F0 ~ F7.
F0 E0
E0 F0
16-bit 16-bit
32-bit
High byte Low byte
E and F index registers are 16-bit data registers
which can be read and written.
If you need a 32-bit register, you have to designate
E. In this case, F will be covered up by E and
cannot be used; otherwise, the contents in E may
become incorrect. (We recommend you use MOVP
instruction to reset the contents in D to 0 when the
PLC is switched on.)
Combination of E and F when you designate a
32-bit index register: (E0, F0), (E1, F1), (E2, F2), …
(E7, F7)