18 Analog I/O Modules (AD268 / DA264 / TC218)
5. I/O Allocation and Programming PART 1 AD268
5.2 A/D conversion data
The analog signals received by the AD268 are converted into the digital data in this module.
These converted digital data are read by T2 CPU in the batch I/O processing and stored in the
assigned input registers as follows.
XW(n) ........ A/D conversion data for channel 1
XW(n+1) .... A/D conversion data for channel 2
XW(n+2) .... A/D conversion data for channel 3
XW(n+3) .... A/D conversion data for channel 4
XW(n+4) .... A/D conversion data for channel 5
XW(n+5) .... A/D conversion data for channel 6
XW(n+6) .... A/D conversion data for channel 7
XW(n+7) .... A/D conversion data for channel 8
The conversion data stored in the XW register is dependent on the input type as follows.
±
±±
±10V range:
A/D conversion data
Input voltage Hex adecimal Integer Resolution
Upper limit +10.2 V H7F80 32640
:: :
Full scale (positive) +10 V H7D00 32000
:: :
+0.3125 mV H0001 1
0 0 V H0000 0
-0.3125 mV HFFFF -1
:: :
Full scale (negative) -10 V H8300 -32000
:: :
Lower limit -10.2 V H8080 -32640
0.3125 mV / bit
+10.2V
HC000
-16384
0
H3FFF
16383
+10V
H7D00
32000
+5.1196V-5.12V-10.2V
-10V
H8300
-32000
Digital value
Analog input
D = 3200 × A
D: Digital data
A: Analog signal (V)
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