Spectrum Controls 1746sc-NI8u - Manual (Page 52)

40 SLC 500 ™ Universal Analog Input Module
Proportional Counts to Engineering Units
Equation: Engr Units Equivalent = S
LOW
+ {(S
HIGH
-S
LOW
) x [(Proportional Counts value displayed + 32768)/65536]}
Assume type E input type, proportional counts display type, channel data =
21567.
Want to calculate °F equivalent.
From Channel Data Word Format table, S
LOW
= -454°F an d S
HIGH
=1832°F
Solution: Engr Units Equivalent = -454°F + {[1832°F -(-454°F)] x [(21567 + 32768)/65536]} = 1441.3°F
Engineering Units to Proportional Counts
Equation: Proportional Counts Equivalent = {65536 x[(Engineering Units desired - S
LOW
)/(S
HIGH
-S
LOW
)]} -32768
Assume type E input type, proportional counts display type, desired channel
temp. = 1000°F.
Want to calculate Proportional Counts equivalent.
From Channel Data Word Format table, S
LOW
= -454°F and S
HIGH
= 1832°F.
Solution: Proportional Counts Equivalent = {65536 x[{1000°F - (-454°F))/(1832°F - (-454°F))]} - 32768 = 8916.