Panasonic FP Series Programming Manual page 385

Arithmetic instructions
F38_DDEC
Subtracts "1" to the 32-bit data specified by d if the trigger EN is in the ON-state. The result is
Description
stored in d.
Example value 131081
Bit
31 . . 28 27 . . 24 23 . . 20 19 . . 16
d
Result 131080
Bit
31 . . 28 27 . . 24 23 . . 20 19 . . 16
d
This instruction also exists as a P instruction (for FP2/2SH, FP3/5, FP10/10SH PLC types), which
is only executed at the rising edge of the EN trigger. Select [Insert P instruction] from the
"Instructions" pane if you require a P instruction. To facilitate reuse, the instruction then appears
under "Recently used" in the pop-up menu. Press <Ctrl>+<Shift>+<v> within the programming
area to open the list of recently used elements.
Availability of F38_DDEC (see page 1325)
PLC types
Data types
Variable Data type
ANY32
d
Operands
For
d
Error flags
No. IEC address
%MX0.900.11
R900B
%MX0.900.9
R9009
In this example the function has been programmed in ladder diagram (LD) and structured text
Example
(ST).The same POU header is used for all programming languages.
POU header All input and output variables used for programming this function have been declared in the POU
header.
384
32-bit decrement
0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0
Function
32-bit area to be decreased by 1
Relay
- DWY DWR DWL DSV
Set
for an instant
for an instant
15 . . 12 10 . . 8 7 . . 4 3 . . 0
0 0 0 0 0 0 0 0 0 0 0 0
32-bit area
15 . . 12 10 . . 8 7 . . 4 3 . . 0
0 0 0 0 0 0 0 0 0 0 0 0
T/C Register
DEV DDT DLD DFL
If
 the calculated result is 0.
 the result exceeds the range of 32-bit
data (underflow).
1 0 0 1
1 0 0 0
Constant
-