User's Manual

6 Standard Function Blocks
6.4 CTD(_E)
212
FXCPU Structured Programming Manual
(Application Functions)
6.4 CTD(_E)
Outline
This function block counts down the number of times of rising of a signal.
1. Format
*1. Refer to caution points.
2. Set data
In explanation of functions, I/O variables inside ( ) are described.
Explanation of function and operation
This function block counts down (subtracts "1" from) the value stored in a device specified in when a
device specified in turns ON.
The value specifies the initial value for subtraction.
This function block turns ON a device specified in when the count value becomes "0".
When a device specified in turns ON, this function block turns OFF a device specified in , and sets
the initial value for subtraction specified in to the count value of a device specified in .
Cautions
1) Use the function having "_E" in its name to connect a bus.
2) Expression of function blocks in each language
*1. Set the instance when using a function block.
Describe the instance name when programming a function block.
FX3U(C) FX3G FX2N(C) FX1N(C) FX1S FX U /FX 2C FX0N FX0(S)
Function name
Expression in each language
Structured ladder ST
CTD
CTD(CD,LOAD,PV); *1
Example:
Instance name(CD:=M0,
LOAD=M10, PV=D0);
M20:=Instance name.Q;
D10:=Instance name.CV;
CTD_E
CTD_E(EN,CD,LOAD,PV); *1
Example:
Instance name(EN=X000,
CD:=M0, LOAD=M10, PV=D0);
M20:=Instance name.Q;
D10:=Instance name.CV;
Variable Description Data type
Input
variable
EN Execution condition Bit
CD ( )
Count source signal Bit
LOAD ( )
Reset input signal Bit
PV ( )
Counter set value Word [signed]
Output
variable
ENO Execution status Bit
Q()
Output signal (which turns ON when the current counter value
becomes "0" or less)
Bit
CV ( )
Number of times of rising Word [signed]
CTD
Q
M20CDM0
CV D10LOADM10
PVD0
Instance name
CTD_E
EN ENO
Q
M20
X000
CDM0
CV D10LOADM10
PVD0
Instance name
s1
s2
n
d1
d2
d2
s1
n
d1
s2 d1
n d2