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:
1. Convert hexadecimal reading to binary.
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)
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
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
Result PF = -0.996
פורסם עבור: שניידר אלקטריק ישראל
