Convert analog output data, Compute the analog output – Rockwell Automation 1746-FIO4V SLC 500 Fast Analog I/O/ User Manual User Manual
Page 34

Publication 1746-UM009B-EN-P - September 2007
34 Processor and Module Considerations
Convert Analog Output Data
The module converts 16-bit binary values from the output image table
to 14-bit analog output signals and left-justifies the bit code in the
channel word. The output range, decimal representation for the
output range, number of significant bits, and converter resolution are
as shown in the following table.
Compute the Analog Output
Use the following formula to compute the output image-table value
(decimal representation) required for a desired analog-output signal
level (to the output device).
EXAMPLE
For example, if the input image table value is 409 from a 4…20
mA sensor.
Analog Output Data
Module
Output Range
Decimal
Representation
(output image table)
Significant
Bits
Resolution
FIO4I
0…21 mA – 1LSB
0…+32,764
13 bits
2.56348 µA/LSB
0…20 mA
0…+31,208
12.92 bits
4…20 mA
6242…31,208
12.6 bits
FIO4V
–10…+10V dc –
1LSB
–32,768…+32,764
14 bits
1,22070 mV/LSB
0…10V dc – 1LSB
0…32,764
13 bits
0…5V dc
0…16,384
12 bits
1…5V dc
3277…16,384
11.67 bits
Full Scale Input
Full Scale Count
Sensor Signal =
x Input Image Value = 0.00977 x 409 = 4 mA
Full-scale Decimal Representation
Full-scale Output
Output Image Value =
x Desired Signal Level