Analog And Digital Value Conversions - Automation Direct DL405 User Manual

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F4–04AD 4-Channel Analog Input
Analog and Digital
Value Conversions
Sometimes it is helpful to be able to quickly convert between the signal levels and
the digital values. This is especially useful during machine startup or
troubleshooting. The following table provides formulas to make this conversion
easier.
Range If you know the digital value
...
0 to 5V
A +
0 to 10V
A +
1 to 5V
A +
4 to 20mA
A +
0 to 20mA
A +
$5V
A +
$ 10V
A +
For example, suppose you are using the
4 to 20 mA input range. If you know the
input signal measures 9 mA, just use the
appropriate formula from the table. It will
give you the the digital value the module
sends to the CPU.
As a bipolar example, suppose you are
$ 10V
using the range. If you know the
CPU receives 2893 counts and the sign
bit is set, just insert –2893 into the
appropriate formula from the table. It will
give you the analog voltage that is
present at the connector for the
corresponding channel.
If you know the analog signal level
...
5(D)
4095
10(D)
4095
4(D)
) 1
4095
16(D)
) 4
4095
20(D)
4095
5(D)
4095
10(D)
4095
D + 4095
(A)
5
D + 4095
(A)
10
D + 4095
(A * 1)
4
D + 4095
(A * 4)
16
D + 4095
(A)
20
4095(A)
D +
5
4095(A)
D +
10
D + 4095
(9–4)
16
D + 256 (5)
D + 1280 counts
10 (–2893)
A +
4095
A + –28930
4095
A + –7.06 Volts