Toshiba AD268 User Manual page 28

6. Parameters
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.
Analog input
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 = (X
2 1
X : Initial A/D conversion value
1
X : Gain/offset processed value
2
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
10V
0 to 10V
5V
0 to 5V
0 to 20mA
1 to 5V
4 to 20mA
Input type
All types
26
Analog I/O Modules (AD268 / DA264 / TC218)
CTi Automation - Phone: 800.894.0412 - Fax: 208.368.0415 - Web: www.ctiautomation.net - Email: info@ctiautomation.net
A/D
conversion
+ O) G / FS
Gain calibration value
Upper limit
Default value
Lower limit
Upper limit
Default value
Lower limit
Upper limit
Default value
Lower limit
Offset calibration value
Upper limit
Default value
Lower limit
Offset
processing processing
32000
32000
10000
16000
16000
5000
12800
12800
4000
3200
0
-3200
PART 1 AD268
A/D conversion data
Gain
(read by T2 CPU)