Mitsubishi Electric FX2N Beginners Manual page 78

Programming Tips for Timers and Counters
E
WARNING:
If you use normal registers the setpoint values will be lost when the power supply is
switched off and when the RUN/STOP switch is set to the STOP position. If this happens
hazardous conditions may be created next time the power is switched on and/or when
the PLC is started again, because all the setpoints will have a value of "0".
If you don't configure your program to copy the values automatically you should always
use latched data registers for storing the setpoint values for timers and counters. Also,
remember that even the contents of these registers will also be lost when the PLC is
switched off if the backup battery is empty.
Setting setpoints with the integrated potentiometers
The controllers of the FX
potentiometers with which you can adjust setpoint values for timers and other functions quickly
and easily.
Potentiometer
Ladder Diagram
X001
0
T1
4
T1
8
In the program example above Y0 is switched on after the delay specified for timer T1, for the
time specified for timer T2 (delayed pulse generation).
4 – 16
, FX , FX
1S 1N 3G
0 1 2 3
4 5 6 7
8 9 10 11
12 13 14 15
IN
POWE R
RUN
ERRO R
FX -24MR
1N
OUT
0 1 2 3
4 5 6 7
10 11
MI TS UB ISH I
D8030
T1
D8031
T2
T2
Y000
, FX and FX series have two integrated analog
3GE 3S
The image on the left shows a basic unit of the
FX series. The layout of the potentiometers is
1N
similar in the FX , FX
1S
The value of the upper potentiometer (VR1) can
be read from special data register D8031, the
value of the lower potentiometer (VR2) from regis-
ter D8031. To use one of the potentiometers as the
setpoint value source for a timer you just specify
the corresponding register in your program ins-
tead of a constant.
The value in the register can be adjusted between
0 and 255 by turning the potentiometer.
Instruction List
0 LD
1 OUT
4 LD
5 OUT
8 LD
8 ANI
10 OUT
Devices in Detail
, FX and FX series.
3G 3GE 3S
X001
T1 D8030
T1
T2 D8031
T1
T2
Y000
MITSUBISHI ELECTRIC