Analog Data Bits - Automation Direct DL405 User Manual

Analog Data Bits

The first twelve bits of the V-memory
location represent the analog data in
binary format.
Bit
0
1
2
3
4
5
Since the module has 12-bit resolution, the analog signal is made of 4096 "pieces"
ranging from 0 – 4095 (2
to get a 0V signal, and 4095 to get a 10V signal. This is equivalent to a binary value
of 0000 0000 0000 to 1111 1111 1111, or 000 to FFF hexadecimal. The following
diagram shows how this relates to each signal range.
Each "count" can also be expressed in
terms of the signal level by using the
equation shown. The following table
shows the smallest signal change that
occurs
increased.
$10V
$5V
0 to 5V
0 to 10V
4 to 20mA
Now that you understand how the analog signal is represented by the digital value,
you're ready to write the control program.
Value Bit
1 6
2 7
4 8
8 9
16 10
32 11
12
–10V to +10V
–5V to +5V
+V
0V
–V
0 4095
when the digital value is
Signal Range
F4–04DA 4-Channel Analog Output
MSB
Value
1 1
64
5 4
128
256
512
1024
2048
). For example, with a 0 to 10V scale, you would send a 0
0V – 10V
0V – 5V
+V
0V
0 4095
Resolution + H * L
H = high limit of the signal range
L = low limit of the signal range
Span Divide By
(H – L)
20V 4095
10V 4095
5V 4095
10V 4095
16mA 4095
V40501
1 1 1 1 9 8 7 6 5 4 3 2 1
3 2 1 0
– data bits
4 – 20mA
20mA
4mA
0 4095
4095
Smallest Change
4.88 mV
2.44 mV
1.22 mV
2.44 mV
3.91 mA
12–11
LSB
0