ZiLOG Z80-AIO Hardware User Manual page 27

adjustment is made at -10V + 2.44mV = -9.9976V
and the gain adjustment at +10V -7.32mV = +9.9926V.
Before making these adjustments, however, the unit
30 minutes under power).
The offset adjustment is made first.
program is then run, and after 100 conversions, it will
halt at the break point.
should be compared.
of times the conversion results exactly matched the reference
The contents of Register C is the number of times the
conversion results did not match the reference value.
Ideally, Register B should have a value of 64H and Register C
should have a value of 0.
indicates an acceptable offset or gain adjustment setting.
The gain adjustment is roade in much the same manner.
The appropriate gain voltage is then applied, and the
calibration procedure performed äs described for the
offset adjustment.
Range
(+/-)5V
0 to +10
0 to +5
TABLE 5.3.1: Data Acquisition Calibration Values
Note: ADC gain adjustment
RV6: ADC offset adjustment
The offset
The contents of B and C registers
The contents of Register B is the number
However B = 50 and C = 50
Offset
-9.9976V
-4.9988V
-2.4994V
+1.22mV
19
The calibration
Gain