Mitsubishi Electric MELSEC FX Series User Manual page 146

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
M34
Auto tuning is
being performed (CH1)
X004
Performs auto tuning (CH1)
M0
An error is present
M24
CH1 Alarm1
140
TO K0 K255
P
TO K0 K253
P
TO K0 K253
P
TO K0 K29
P
TO K0 K29
P
TO K0 K56
P
TO K0 K56
P
9.3 Example of a Program for Heating/Cooling 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.
K0 K1
When X003 turns ON, control
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.)
When X004 is set to ON, auto
tuning is performed.
Once auto tuning has started, it
K0 K1
continues even if X004 is set to
OFF after that.
When the flag (M34) turns OFF
while auto tuning is performed, it is
judged that auto tuning is
K1 K1
completed. Then, "K0" is written to
BFM#56.
Because of this, auto tuning can be
performed again.
If auto tuning does not have to be
performed again, the upper two
lines can be omitted.
(M34 turn ON and off in accordance
with the event status.)
An error is present
Y000
CH1 Alarm1
Y001
END
9 Program Examples