356
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
Cautions
1. Setting the pulse width and cycle
Make sure that the pulse width
and cycle
satisfy the relationship "
≤
".
2. Pulse output
• Only the following outputs can be specified in
according to the system configuration.
- When using special high speed output adapters
*1
: Y000, Y001, Y002
*2
, or Y003
*2
- When using transistor outputs in the main unit (that is, when not using special high speed output
adapters): Y000, Y001, or Y002
*1.
Special high speed output adapters cannot be connected to the FX
3UC
-32MT-LT.
When using PWM (FNC 58) instruction in a relay output type FX
3U
PLC, a special high speed output
adapter is required.
*2.
For specifying Y002 or Y003 in a special high speed output adapter, the second special high speed
output adapter is required.
• The pulse output is controlled by the interrupt processing not affected by the sequence program (operation
cycle).
• If the command input is set to OFF, the output from
turns OFF.
• While a pulse output monitor (BUSY/READY) flag is ON, a pulse output instruction and positioning
instruction for the same output relay cannot be executed.
While a pulse output monitor flag is ON even after the instruction drive contact is set to OFF, do not
execute a pulse output instruction or positioning instruction for the same output relay.
For driving such an instruction, wait until the pulse output monitor flag turns OFF and one operation cycle
or longer period passes after that, and then execute such an instruction again.
3. Cautions on using special high speed output adapters
1) Outputs of special high speed output adapters work as differential line drivers.
2) Set the pulse output type setting switch in a special high speed output adapter to "pulse chain + direction"
(PLS
x
DIR) side.
If the switch is set to "forward rotation pulse chain, reverse rotation pulse chain" (FP
x
RP) side, normal
operations are disabled because the pulse output destination switches depending on the output status as
shown in the table below.
3) Set the pulse output type setting switch while the PLC is stopped or while the power is OFF.
Do not manipulate the pulse output type setting switch while pulses are being output.
Pulse output destination device
Pulse output monitor flag
Y000
M8340
Y001
M8350
Y002
M8360
Y003
M8370
Pulse output
destination
Output giving effect
on operation
Operation
=
Y000
Y004
While Y004 is ON in PLC, pulses are output from Y000 in high speed output
adapter.
While Y004 is OFF in PLC, pulses are output from Y004 in high speed output
adapter.
=
Y001
Y005
While Y005 is ON in PLC, pulses are output from Y001 in high speed output
adapter.
While Y005 is OFF in PLC, pulses are output from Y005 in high speed output
adapter.
=
Y002
Y006
While Y006 is ON in PLC, pulses are output from Y002 in high speed output
adapter.
While Y006 is OFF in PLC, pulses are output from Y006 in high speed output
adapter.
=
Y003
Y007
While Y007 is ON in PLC, pulses are output from Y003 in high speed output
adapter.
While Y007 is OFF in PLC, pulses are output from Y007 in high speed output
adapter.
S
1
S
2
S
1
S
2
D
D
D
D
D
D