Voltage Input Characteristics - Mitsubishi Electric MELSEC A Series Manual

3. SPECIFICATIONS
3.3.1

Voltage input characteristics

1/4000
setting
4095
2000
Digital
output
value
0
-4096
Setting Offset
Example No. Value
1 0 V
2 0 V
3 -5 V
Figure 3.2 shows the voltage input characteristics for three different offset/gain
combinations.
1/8000 1/12000
setting setting
8191 12287
4000 6000
0 0
-8192 -12288
Digital Output Value with +3 V
Gain
value
1/4000
Setting
2.5 V 2400
5 V 1200
10 V 1066
Figure 3.2 Voltage Input Characteristics
POINTS
(1) If the input voltage is in the range of -10 to 0 to 10 V, the maximum re-
solution and overall accuracy are within the range of performance specifi-
cations. However, if the input voltage exceeds this range, resolution and
accuracy will be impaired
(2) Inputting an analog voltage that causes the digital output value to exceed
the maximum value (4095/8191/12287) or to become smaller than the
minimum value (-4096/-8192/-12288), locks the result of the A-D conver-
sion (digital output value) at either the maximum value (4095/8191/12287)
or the minimum value (-4096/-8192/-12288).
(3) Do not apply ± 15 V or more. This will damage the module.
(4) When setting the gain or offset, the following must be satisfied:
(Gain value) – (Offset value) ≥ 1 V (1/4000 setting)/1.5 V (1/8000
setting)/2 V (1/12000 setting)
If the set values do not satisfy the relationship stated above, the obtained
digital output values will not be correct.
Practical analog input range
-5
-15 -10
Analog input voltage (V)
Analog Input
1/8000 1/12000
Setting Setting
4800 7200
2400 3600
2132 3198
3 − 4
Setting example [1]
Set value: 0 V
Gain value: 25 V
Setting example [2]
Offset value: 0 V
Gain value: 5 V
5
Setting example [3]
Offset value: -5 V
Gain value: 10 V
0 10 15
Digital Output Value with -3 V
Analog Input
1/4000 1/8000
Setting Setting
-2400 -4800
-1200 -2400
266 532
MELSEC-A
1/12000
Setting
-7200
-3600
798