Mitsubishi Electric FX2N-2DA User Manual page 4

7. ADJUSTMENT OF OFFSET AND GAIN
7.1 Change in output characteristic
At shipment, 0 to 4000 range is selected for 0 to 10V DC output.
When using an FX
2N
readjust the offset and gain.
The output characteristic can be set for each of the two channels.
Set analog values within the range specified in the table below when changing the output characteristic.
Range of output characteristic
Analog value when digital value is 0
Analog value when digital value is 4000
Resolution changes depending on the set value when the output characteristic changes accordingly.
Example: Resolution becomes (5 - 0V)/4000=1.25mV at voltage output 0 to 5V/0 to 4000.
Integrated accuracy does not change. (Voltage output: ± 0.1V, Current output: ± 0.16mA)
7.2 Adjustment of the output characteristic
The adjustment of the offset and gain values sets a digital equivalent to the analog data.
(The "POT" requires 18 revolutions to move between MIN and MAX setting.)
Voltage output
FX -2DA
2N
VOUT
IOUT
COM
*1 The analog value increases if the volume is turned clockwise.
7.2.1 Adjustment of gain
The gain value can be set to an arbitrary digital value.
However, using the maximum of 12bit resolution provides the user with a full scale analog value.
Voltage output
characteristic (0 to 10V)
at shipment
10V
0
Digital value
7.2.2 Adjustment of offset
The offset value in the case of voltage output is 0V. The offset value in the case of current output is 4mA.
However, the offset value can be minutely adjusted if necessary. Set the following when minute
adjustments are necessary.
Voltage output
characteristic (0 to 10V)
at shipment
100mV
0
Digital value
For instance, when a digital range of 0 to 4000 is used with the analog range of 0 to 10V, a digital value of
40 is equal to an analog output of 100mV, (40 × 10V/4000 digital points). When a digital range of 0 to 4000
is used with the analog range of 4 to 20mA, a digital value of 0 is equal to an analog output of 4mA.
1) Adjust the offset and gain respectively for CH1 and CH2.
2) Repeat offset and gain adjustments until a stable value is obtained.
3) Adjust the gain before the offset.
-2DA for current or differing voltage output except 0 to 10V DC, it is necessary to
Current output
FX -2DA
2N
+
Voltmeter
V
-
4000
100m V
40
Voltage output
0 to 1V
5 to 10V
VOUT
+
IOUT
Ammeter
A
COM
-
Voltage output
characteristic (0 to 5V)
5V
0 4000
Digital value
V oltage output
characteristic (0 to 5V )
0 80
D igital value
Current output
4mA
20mA
Volume *1
CH1
Offset volume
CH1
OFFSET
CH1
CH1
Gain volume
OFFSET
POWER
POWER
CH2
Offset volume
CH1
GAIN CH1
CH2
GAIN
OFFSET
CH2 CH2
CH2
GAIN
OFFSET
CH2
Gain volume
GAIN
Current output
characteristic (4 to 20mA)
20m
A
4mA
0 4000
Digital value
Current output
characteristic (4 to 20mA)
4mA
0
Digital value