Unipolar Resolution; Bipolar Resolution - Automation Direct DL405 User Manual

3–22
F4–04AD 4-Channel Analog Input
Unipolar
Resolution

Bipolar Resolution

Each count can also be expressed in
terms of the signal level by using the
equation shown. Unipolar ranges have
12 bits of resolution, which divides the
signal span into 4095 counts. The
following table shows the smallest signal
change that will result in a single LSB
change in the data value for each signal
input range.
Range Signal Span
(H – L)
0 to 5V 5 V
0 to 10V 10 V
1 to 5V 4 V
4 to 20mA 16 mA
0 to 20mA 20 mA
Bipolar ranges have 13 bits of resolution,
(the additional sign
additional bit of resolution). This divides
the signal span into 8191 counts. The
following table shows the smallest signal
change that will result in a single LSB
change in the data value for each signal
input range.
Range Signal Span
(H – L)
–5 to +5V 10 V
–10 to +10V 20 V
Now that you understand how the module and CPU work together to collect and
store the information, you're ready to write the control program.
Unipolar resolution + H–L
H = High limit of the input signal
L = Low limit of the input signal
Divide By
4095
4095
4095
4095
4095
bit adds an
Bipolar resolution + H–L
H = High limit of the input signal
L = Low limit of the input signal
Divide By
8191
8191
4095
Smallest Detectable
Change
1.22 mV
2.44 mV
0.98 mV
3.91 mA
4.88 mA
8191
Smallest Detectable
Change
1.22 mV
2.44 mV