IDEC FC4A-C10R2 User Manual page 278

16: I I
NTERFACE NSTRUCTIONS
Adjusting Scan Time
The DGRD instruction requires a scan time longer than the filter time plus 6 ms.
Minimum Required Scan Time
(Scan time) ≥ (Filter time) + 6 ms
The filter time depends on the input terminal used as shown below.
Input Terminals
I0 through I7 on CPU Modules
I10 through I15 on CPU Modules
(except slim 40-I/O type CPU Module)
I10 through I27 on slim 40-I/O type CPU Module
Inputs on Expansion Input Modules
When the actual scan time is too short to execute the DGRD instruction, use the constant scan function. When the input fil-
ter time is set to 3 ms, set a value of 9 or more (in ms) to special data register D8022 (constant scan time preset value). See
page 5-27. When the input filter time is changed, set a proper value to D8022 to make sure of the minimum required scan
time shown above.
Example: DGRD
The following example demonstrates a program to read data from four digital switches (IDEC's DFBN-031D-B) to a data
register in the CPU module, using a 8-point DC input module and a 16-point transistor sink output module.
DGRD
BCD4 I30
I5
I/O Wiring Diagram
16-4
I Q D1
Q30 D10
8-point DC Input Module
FC4A-N08B1
I30
I31
I32
I33
I34
I35
I36
I37
COM
COM
(+) 24V DC
Power
(–)
Supply
« FC4A M
Filter value selected in the Function Area Settings (default 3 ms)
See Input Filter on page 5-24.
3 ms (fixed)
4 ms (fixed)
4 ms (fixed)
When input I5 is on, the 4-digit value from BCD digital switches is read to
data register D10.
16-point Transistor
Sink Output Module
FC4A-T16K3
Q30
Q31
Q32
Q33
Q34
Q35
Q36
Q37
COM(–)
+V
S U ' M
ICRO MART SER S ANUAL
Filter Time
Digital
Switches
C 8
4
2
1
C 8
4
2
1
C 8
4
2
1
C 8
4
2
1
»
0
10
1
10
2
10
3
10