user manual

26
Analog I/O Modules (AD268 / DA264 / TC218)
6. Parameters
PART 1 AD268
Gain calibration value & Offset calibration value:
(Gain: H8000 to H8007, Offset: H8008 to H800F)
At the factory shipment, the AD268 is calibrated for each input range. Therefore, there is no
need for user to calibrate normally.
However, depending on the usage condition, field adjustments are required. For this purpose,
the AD268 has the gain and offset calibration function.
In the AD268, the A/D conversion data is calculated as follows.
When the gain calibration value is G and the offset calibration value is O, the conversion
calculation is performed in the AD268 as follows.
X
2
= (X
1
+ O) × G / FS
X
1
: Initial A/D conversion value
X
2
: Gain/offset processed value
O: Offset calibration value (buffer memory address H8008 to H800F)
G: Gain calibration value (buffer memory address H8000 to H8007)
FS: Full scale value
32000 for ±10V and 0 to 10V ranges
16000 for ±5V, 0 to 5V and 0 to 20mA ranges
12800 for 1 to 5V and 4 to 20mA ranges
The data setting range of the gain and offset calibration value are as follows.
Input type Gain calibration value
Upper limit 32000
Default value 32000
±10V
0 to 10V
Lower limit 10000
Upper limit 16000
Default value 16000
±5V
0 to 5V
0 to 20mA
Lower limit 5000
Upper limit 12800
Default value 12800
1 to 5V
4 to 20mA
Lower limit 4000
Input type Offset calibration value
Upper limit 3200
Default value 0All types
Lower limit -3200
Analog input
A/D
conversion
Offset
processing
Gain
processing
A/D conversion data
(read by T2 CPU)
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