398
FX
3G
/FX
3U
/FX
3UC
Series Programmable Controllers
Programming Manual - Basic & Applied Instruction Edition
13 High Speed Processing – FNC 50 to FNC 59
13.9 FNC 58 – PWM / Pulse Width Modulation
4) When special high speed output adapters are connected, the same output numbers in the main unit are
assigned as shown in the table below.
Only wire the appropriate output terminals.
Outputs in special high speed output adapters and the main unit operate as shown below.
Assignment of output numbers in special high speed output adapters
Output operation
Program example
When the contents of D10 are changed in the range from "0" to "50" in the program example shown below,
the average output from Y000 will be in the range from 0 to 100%.
In this program example the FX
3U
series main unit (sink output) is used. For wiring details, refer to the
following manual.
→
FX
3G
Hardware Edition
→
FX
3U
Hardware Edition
→
FX
3UC
Hardware Edition
Example of smoothing circuit
R
>
P
τ
= P(k
Ω
)
°
C(
µ
F) = 470ms
>>
T
0
The time constant of the filter should be considerably larger than the pulse cycle T
0
.
The ripple value "
∆
e" in the mean output current "e" is approximately "
∆
e/e
≤
T
0
/
τ
"
Setting status of output
form setting switch
Signal name
Setting name in each
positioning instruction
Output number
1st unit
2nd unit
1st axis 2nd axis 3rd axis 4th axis
"FP
x
RP" side
Forward rotation
pulse chain (FP)
Pulse output destination
Y000
Y001
Y002
Y003
Reverse rotation
pulse chain (RP)
Rotation direction signal
Y004
Y005
Y006
Y007
"PLS
x
DIR" side
Pulse chain
Pulse output destination
Y000
Y001
Y002
Y003
Direction
Rotation direction signal
Y004
Y005
Y006
Y007
Output operation
Relay output type main unit
Do not use the PWM (FNC 58) instruction with relay-output type main units.
(Considerable output response delay may be generated, chattering may occur
in contacts, or the contact life may be shortened.)
Special high speed output adapter
Set the output frequency to "200kHz" or less.
Use a transistor output type main unit.
Transistor output type main unit
Set the output frequency to "100kHz" or less.
X0
D10
K50
Y000
FNC 58
PWM
D10
50ms
Y000
Y000
COM1
Y001 Y002 Y003
PLC
510
Ω
12V
1k
Ω
E
e
V
+
C
470
µ
F
10V
5V
1k
Ω
1k
Ω
1k
Ω
R
(1k
Ω
)
P
22
Ω
24V
0V