Rockwell Automation 1746-NI16V SLC 500 Analog Input Modules User Manual - Manual (Page 62)

Publication 1746-UM001A-US-P
5-14 Channel Configuration, Data, and Status
Scaled-for-PID to Real Units
Example: #3 A transducer is being used to measure temperature.
The 4 to 20 mA signal range is proportional to 100 to 500°C (212 to 932°F)
The input data is scaled for PID, i.e. input range of 0 to 16383
Input value to convert = 5500
The scaled range is 212 to 932°F
The Input range is 0 to 16383
Find: Input value in °F
Per the equation above:
Proportional Counts to Real Units
Example: #4 A transducer is being used to measure pressure.
The -10V dc to +10V dc signal range is proportional to 0 to 200 psi
The input data is in “Proportional Counts” data format, i.e. -32768 to 32767
Input value to convert = 21567
The Scaled range is 0 to 200 psi
The Input range is -32768 to 32767
Find: Input value in psi
Per the equation above:
Slope
932 212 –
( )
16383 0 –
( )
-------------------------------- 0.044 = =
Offset 212 0 0.044
× ( )
212 = – =
Scaled Value 5500 0.044
× ( )
212 454
°
F = + =
Slope
200 0 –
( )
32767 32768 –
( )
–
[ ]
------------------------------------------------------ 0.003 = =
Offset 0 32768 0.003
( )
–
( )
98.3 = – =
Scaled Value 21567 003
× ( )
98.3 163 psi = + =