Mitsubishi Electric FX2N-2AD User Manual page 8

7. Adjustment of offset and gain
7.1 Change in input characteristic
At shipment, 0 to 4000 range is selected for 0 to 10V DC input.
When using an FX -2AD for current or differing voltage inputs except 0 to 10V DC, it is necessary to
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adjust the offset and gain.
The module does not allow different input characteristics for two channels.
Set analog values within the range specified in the table below when changing the input characteristic.
Range of input characteristic
Voltage input
Analog value when digital value is 0 0 to 1V
Analog value when digital value is 4000 5 to 10V
Resolution changes depending on the set value when the input characteristic changes accordingly.
Example: Resolution becomes (5 - 0V)/4000=1.25mV at voltage input 0 to 5V/0 to 4000.
±
Integrated accuracy does not change. (Voltage input : 0.1V, Current input:
7.2 Adjustment of the input characteristic
The adjustment of the offset and gain values sets a digital equivalent to the analogue data.
(The "POT" requires 18 revolutions to move between MIN and MAX setting.)
Voltage input Current input
FX -2AD + - FX
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VIN VIN
A
+ + +
Voltage Current
V
IIN IIN
generator generator
- -
COM COM
*1 The digital value increases if the volume is turned clockwise.
(FX -4DA and FX -2DA can be used instead of the voltage and current generator)
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7.2.1 Adjustment of gain
The gain value can be set to an arbitrary digital value.
However, using the maximum 12bit resolution provides the user with a digital range of 0 to 4000.
Voltage input
Voltage input
characteristic(0 to 10V)
characteristic(0 to 5V)
At shipment
4000
4000
0 10V
0 5V
Analog value Analog value
7.2.2 Adjustment of offset
The offset value can be set to an arbitrary digital value. However, it is advisable to set the analog value
when the digital value is set as following.
Voltage input Voltage input
characteristic(0 to 10V)
characteristic(0 to 5V)
At shipment
40 80
0 100mV 0 100mV
Analog value Analog 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 input of 100mV. (40 × 10V/4000 digital points)
1) The offset and gain adjustments for CH1 and CH2 are accomplished at the same time. When the
offset and gain values of one channel are adjusted, the other channel is automatically adjusted.
2) Repeat the offset and gain adjustment alternately until a stable value is reached.
3) Each channel is common to the analog input circuit. However, check each channel individually for
maximum accuracy.
4) Adjust offset / gain by using subsection 8-3 "Example of programming making average value data"
when a digital value is not steady.
5) Adjust the gain before the offset.
8. Program example
The following program examples (8.1 and 8.3) are formula circuits.
The device numbers that have been underlined can be assigned by the user during programming.
8.1 Example of programming analog input
X000
0
*1
Current input
X001
0 to 4mA
33
20mA
*1
±
0.16mA)
Analog to digital conversion execution input of CH1:X000
Analog to digital conversion execution input of CH2:X001
At the same time X000 and X001 can be turned ON.
A/D input data CH1 :D100 (Replace with auxiliary relay M100 to M115. Assign these numbers only once)
Volume
A/D input data CH2 :D102 (Replace with auxiliary relay M100 to M115. Assign these numbers only once)
*1
-2AD
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Processing time: 2.5ms / 1 channel
A/D
OFFSET
POWER
volume
OFFSET
GAIN AD GAIN
OFFSET volume
GAIN
*1 Change the circuit of "*1" as follows when using an FX
Current input
8.2 Connection to FX
characteristic(4 to 20mA)
or FX series PLC
3UC
4000
Please use FNC 176 (RD3A).
Refer to FX Series Programming Manual ΙΙ or FX
8.3 Example of programming making average value data
Add the undermentioned program after "8.1 Example of programming analog input" and use the average
0 4mA 20mA
value data when you can not read a stable digital value.
Analog value
M8002
0
M133
Current input
characteristic(4 to 20mA)
M8000
39
25
M133
84
0 4mA 4.1mA
Analog value
A/D input data of CH1 :D100
A/D input data of CH2 :D102
Sampling frequency
Agreement flag of sampling frequency and average frequency :M133
Average value of CH1 :D111, D110
Average value of CH2 :D113, D112
*1 The above program example has an average sampling frequency of 20. Make the average frequency
within the range of 2 to 262143.
9. Notes in drive
1) Confirm whether the input wiring of FX
done.
2) Confirm whether the "4. Connection with programmable controller" condition is satisfied.
3) When shipped from the factory, the input characteristic is adjusted to 0 to 10V DC.
If a different input characteristic is desired, please adjust as required.
When the input characteristic is adjusted, the input characteristics of CH1 and CH2 are changed.
4) The coexistence use for the current and voltage input cannot be done with two channels.
[TO K0 K17 H0000 K1 ] a) Selecting A/D input channel 1.
[TO K0 K17 H0002 K1 ] b) A/D conversion beginning of CH1.
c)
[FROM K0 K0 K2M100 K2 ] Reading of digital value of CH1.
d)
The higher 4 bits of CH1 are
[MOV K3M100 D100 ]
moved to the lower 8 bits, and it is
stored in D100.
[TO K0 K17 H0001 K1 ] e)
Selecting A/D input channel 2.
f)
[TO K0 K17 H0003 K1 ] A/D conversion beginning of CH2.
g)
[FROM K0 K0 K2M100 K2 ] Reading of digital value of CH2.
h)
[MOV K3M100 D102 ] The higher 4 bits of CH2 are
moved to the lower 8 bits, and it is
stored in D102.
(Time from turning on X000 and X001 to storage of analog to digital conversion value in
data register of main unit.)
PLC
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[FROM K0 K0 K4M100 K2 ] Reading of digital value
The higher 4 bits are synthesized
[MOV K2M116 K2M108]
to the lower 8 bits.
FX (V3.00 or later), FX (V3.00 or later), FX
1N, 2N 2NC
/FX /FX /FX /FX Programming Manual.
3S 3G 3GC 3U 3UC
[DMOV K0 D114 ]
[DMOV K0 D116 ]
[DMOV K0 D118 ] a a) Initialization of data
[MOV K0 D101 ]
[MOV K0 D103 ]
[DINC D118 ] b b) Count of sampling frequency
[DADD D114 D100 D114 ] c c) Total of input data of CH1
d)
[DADD D116 D102 D116 ] d Total of input data of CH2
*1
e) Comparison of sampling frequencies
[DCMP D118 K20 M132 ] e
K20 is an average frequency
[DDIV D114 D118 D110 ] f
f) The average value of CH1 is calculated,
[DDIV D116 D118 D112 ] g
and the result is stored in D111, D110
g)
The average value of CH2 is calculated,
and the result is stored in D113, D112
:D118
-2AD and the connection of the extension cable is correctly
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10. Error check
Confirm the following items when it seems that the FX
1) Confirm the state of POWER LED.
Lit :The extension cable is correctly connected.
Turn off or blinks :Confirm the proper connection of the extension cable.
2) Confirm the external wiring per section "3. Wiring".
3) Confirm whether the load resistance of the connected equipment corresponds to the specification of
the FX -2AD.
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4) Confirm the Voltage and Current input values with a voltage and current generator. Confirm the
analog to digital conversion from the input characteristic.
5) Readjust the offset and gain by "7. Adjustment of offset and gain" when the analog to digital
conversion is not suitable for the input characteristic.
The input characteristic when shipped from the factory is 0 to 10V DC.
Guidelines for the safety of the user and protection of the FX
FUNCTION BLOCK
• This manual has been written to be used by trained and competent personnel. This is defined
by the European directives for machinery, low voltage and EMC.
• If in doubt at any stage during the installation of the FX
electrical engineer who is qualified and trained to the local and national standards. If in doubt
about the operation or use of the FX
representative.
• Under no circumstances will Mitsubishi Electric be liable or responsible for any consequential
damage that may arise as a result of the installation or use of this equipment.
• All examples and diagrams shown in this manual are intended only as an aid to
understanding the text, not to guarantee operation. Mitsubishi Electric will accept no
responsibility for actual use of the product based on these illustrative examples.
• Owing to the very great variety in possible application of this equipment, you must satisfy
yourself as to its suitability for your specific application.
FX FX
3G, 3GC, 3U
This manual confers no industrial property rights or any rights of any other kind, nor does it
confer any patent licenses. Mitsubishi Electric Corporation cannot be held responsible for any
problems involving industrial property rights which may occur as a result of using the contents
noted in this manual.
Warranty
Exclusion of loss in opportunity and secondary loss from warranty liability
Regardless of the gratis warranty term, Mitsubishi shall not be liable for compensation to:
(1) Damages caused by any cause found not to be the responsibility of Mitsubishi.
(2) Loss in opportunity, lost profits incurred to the user by Failures of Mitsubishi products.
(3) Special damages and secondary damages whether foreseeable or not, compensation for
accidents, and compensation for damages to products other than Mitsubishi products.
(4) Replacement by the user, maintenance of on-site equipment, start-up test run and other tasks.
This product has been manufactured as a general-purpose part for general industries, and has
not been designed or manufactured to be incorporated in a device or system used in purposes
related to human life.
Before using the product for special purposes such as nuclear power, electric power,
aerospace, medicine or passenger movement vehicles, consult with Mitsubishi Electric.
This product has been manufactured under strict quality control. However when installing the
product where major accidents or losses could occur if the product fails, install appropriate
backup or failsafe functions in the system.
Manual number : JY992D74701
Manual revision : G
Date
HEAD OFFICE : TOKYO BUILDING, 2-7-3 MARUNOUCHI, CHIYODA-KU, TOKYO 100-8310, JAPAN
JY992D74701G
-2AD does not operate normally.
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-2AD SPECIAL
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-2AD always consult a professional
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-2AD please consult your local Mitsubishi Electric
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For safe use
: December 2016
Effective December 2016
Specifications are subject to change without notice.