Delta RMC101 - Manual (Page 623)

SSI 6.6
Transducer Interface Modules 6-79
These calculations are done automatically using the SSI Scale/Offset Calibration Utility feature in
RMCWin.
Example 1
A system has an MDT with an SSI interface that has a resolution of 5 microns. The user wishes
to have positions in thousandths of an inch. At the desired 0 position, the MDT produces 3221
counts.
We first calculate the exact Scale:
With the exact Scale value, we must choose the Prescale Divisor and the rounded Scale value.
The highest divisor value we can use is 4; multiplying the scale by 8 would overflow the Scale
limits of ±32767. Therefore we have the following parameters:
Scale = 25802
Prescale Divisor = 4
Next, we must calculate the offset:
Example 2
A system has an MDT with an SSI interface that has a resolution of 2 microns. The user wishes
to have positions in hundredths of a millimeter. At the desired 0 position, the MDT produces 8273
counts.
We first calculate the exact Scale:
With the exact Scale value, we must choose the Prescale Divisor and the rounded Scale value.
The highest divisor value we can use is 4; multiplying the scale by 8 would overflow the Scale
limits of ±32767. Therefore we have the following parameters:
Scale = 26214
Prescale Divisor = 4
Next, we must calculate the offset: