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# Reading Power Factor on a CM4000

Published date: 22 March 2019

Issue
User needs to read the power factor value from a CM4000

Product Line
CM4000

Environment
Modbus

Resolution
Steps to convert the PF reading from hexadecimal to decimal value are below:
2. Remove the first bit (sign bit) of the binary value.
a. If the sign bit is zero (0), the resulting Power Factor is positive (sign multiplier = +1)
b. If the sign bit is one (1), the resulting Power Factor is negative (sign multiplier = -1)
3. Convert the remaining 15-bit value to decimal
4. Multiply resulting decimal value by the scaling factor to obtain the power factor magnitude
5. Multiply the power factor magnitude by the sign multiplier

Example:
Hexadecimal reading of 0x83E4 and scaling factor of 0.001
1. Convert the hexadecimal reading to binary:

0x83E4 (or 33764 in decimal) = 1000001111100100 in binary.
2. Remove the first bit (sign bit) of the binary value. Remaining binary value is 000001111100100
b. The sign bit is 1. Sign multiplier = -1
3. Convert the remaining 15-bit value to decimal
000001111100100 in binary = 996 in decimal
4. Multiply resulting decimal value by the scaling factor to obtain the power factor magnitude
996*0.001 = 0.996
5. Multiply the power factor magnitude by the sign multiplier
0.996*(-1) = -0.996
Result PF = -0.996