Mitsubishi Electric MELSEC FX Series User Manual page 141

FX -4LC User's Manual
3U
From previous page
X001
Performs initialization
X002
Disables error reset
X002
Performs error reset
X003
Stops control
X003
Starts control
M100 M14
Initialization
completed
flag
M34
Auto tuning is
being performed (CH1)
M54
Auto tuning is
being performed (CH2)
X004
Performs auto tuning (CH1)
X005
Performs auto tuning (CH2)
M0
An error is present
M28
CH1 Loop breaking alarm
M48
CH2 Loop breaking alarm
TO K0 K255
P
TO K0 K253
P
TO K0 K253
P
TO K0 K29
P
TO K0 K29
P
TO K0 K54
P
TO K0 K94
P
TO K0 K56
P
TO K0 K96
P
TO K0 K56
P
TO K0 K96
P
9.2 Example of a Program for PID Control
From previous page
Initializes all data.
When X001 is set to ON, all
data is initialized.
K1 K1
(When initialization is not
necessary, this line can be
omitted.)
K0 K1
Error reset command.
When X002 is set to ON, all
errors indicated by the flag
(BFM#0) are reset.
K1 K1
Starts/stops control.
When X003 turns OFF, control
stops.
When X003 turns ON, control
K0 K1
starts.
In order to turn OFF the control
output, this line is required and
cannot be omitted.
K1 K1 (The control output cannot be
set to OFF by changeover from
"RUN" to "STOP" of the PLC
main unit.)
K0 K1
In this example, only the AUTO
mode is used.
When changeover of the mode
is necessary, write "K1" to
BFM#54 and BFM#94 in
K0 K1
accordance with the
changeover condition.
When X004/X005 is set to ON,
auto tuning is performed.
K0 K1
Once auto tuning has started, it
continues even if X004/X005 is
set to OFF after that.
When the flag (M34/M54) turns
OFF while auto tuning is
K0 K1
performed, it is judged that auto
tuning is completed. Then, "K0"
is written to BFM#56/#96.
Because of this, auto tuning can
K1 K1
be performed again.
If auto tuning does not have to
be performed again, the upper
two lines can be omitted.
(M34 and M54 turn ON and off
K1 K1
in accordance with the event
status.)
An error is present
Y000
CH1 Loop breaking alarm
Y001
Y002 CH2 Loop breaking alarm
END
9 Program Examples
1
2
3
4
5
6
7
8
9
10
135