Mitsubishi Electric Q68AD-G User Manual page 18

1
OVERVIEW
(6) High accuracy
(7) Changing the input range
(8) A/D conversion system
(9) Input signal error detection function
(10)Warning output
1.1 Features
1
- 2
*1
The reference accuracy
as ±71.4ppm/°C.
*1 Accuracy of offset/gain setting at ambient temperature
*2 Accuracy per temperature change of 1°C
Example) Accuracy when the temperature varies from 25 to 30°C
0.1% (reference accuracy) + 0.00714 %/°C (temperature coefficient)
(temperature variation difference) = 0.1357%
*3
The input range can easily be set from the GX Developer.
*3 Input range refers to the type of offset/gain settings. The most frequently used range is set as the
default but the user can also set the offset/gain.
There are the following five A/D conversion systems.
(a) Sampling processing
Analog input values are converted into digital values one by one on a channel
basis and the digital output value is output at every conversion.
(b) Averaging processing
1) Time averaging
A/D conversion is averaged in terms of time on a channel basis and a digital
average value is output.
2) Count averaging
A/D conversion is averaged in terms of count on a channel basis and a digital
average value is output.
3) Move averaging
The specified number of digital output values measured per sampling time are
averaged.
(c) Primary delay filter
A digital output value is smoothed according to the preset time constant.
*1 Refer to Section 3.2.1 for the details of the A/D conversion system.
The voltage/current outside the setting range is detected.
*1
There are the following two warning outputs.
(a) Process alarm
A warning is output if a digital output value falls outside the setting range.
(b) Rate alarm
A warning is output if the varying rate of a digital output value falls outside the
preset varying rate range.
*1 Refer to Section 3.2.4 for details on warning output.
is as high as ±0.1% and the temperature coefficient
*1
*2
is as high
5°C