Analog Output Data Representation
VCM-DAS-3 Reference Manual
29
O
FFSET
B
INARY
C
ODING
The formulas for calculating analog or straight binary digital values are given by:
Where:
Analog = Applied voltage
Digital = A/D conversion data
Offset
1
= 2048 for symmetrical ranges
1024 for asymmetrical range
Step
= 0.00122070313 for ±2.5V range
0.00244140625 for ±5V and
-
2.5 to +7.5 ranges
0.0048828125 for ±10V range
Offset
2
= 2.5 for ±2.5V and
-
2.5 to +7.5 ranges
5 for ±5V
10 for ±10V range
Table 20: Offset Binary Data Format – Symmetrical Ranges
±
2.5V
Output
Voltage
±
5V
Output
Voltage
±
10V
Output
Voltage
Hex
Decimal
Comment
+2.5000
+5.0000
+10.0000
–
–
Out of range
+2.4987
+4.9975
+9.9951
FFFh
4095
Maximum positive voltage
+1.2500
+2.5000
+5.0000
C00h
3072
Positive half scale
+0.6250
+1.2500
+2.5000
A00h
2560
Positive quarter scale
+0.00122
+0.00244
+0.00488
801h
2049
Positive 1 LSB
0.0000
0.0000
0.0000
800h
2048
Zero (ground voltage)
-
0.00122
-
0.00244
-
0.00488
7FFh
2047
Negative 1 LSB
-
0.6250
-
1.2500
-
2.5000
600h
1536
Negative quarter scale
-
1.2500
-
2.5000
-
5.0000
400h
1024
Negative half scale
-
2.5000
-
5.0000
-
10.0000
000h
0
Maximum negative voltage
Digital =
Analog = (Step x Digital)
-
Offset
2
+ Offset
1
Analog
Step