PLC Digital Signal · Free Calculator
PLC Status Word and Bit Decoder
Decode a drive status word, alarm word or PLC fault word: enter the value and see every bit that is on, with its weight in decimal and hex.
Bit by bitHex and binaryDrive status word16 and 32 bit
Bits set0, 1, 5, 10, 15
Decimal33827
Hex0x8423
Binary1000 0100 0010 0011
As signed−31709
Bit map
| Bit | State | Weight | Hex |
|---|---|---|---|
| Bit 0 | ON | 1 | 0x1 |
| Bit 1 | ON | 2 | 0x2 |
| Bit 2 | off | 4 | 0x4 |
| Bit 3 | off | 8 | 0x8 |
| Bit 4 | off | 16 | 0x10 |
| Bit 5 | ON | 32 | 0x20 |
| Bit 6 | off | 64 | 0x40 |
| Bit 7 | off | 128 | 0x80 |
| Bit 8 | off | 256 | 0x100 |
| Bit 9 | off | 512 | 0x200 |
| Bit 10 | ON | 1024 | 0x400 |
| Bit 11 | off | 2048 | 0x800 |
| Bit 12 | off | 4096 | 0x1000 |
| Bit 13 | off | 8192 | 0x2000 |
| Bit 14 | off | 16384 | 0x4000 |
| Bit 15 | ON | 32768 | 0x8000 |
Advertisement
Reading a Status Word
Word value = Σ 2bit for every bit that is on
Bit 0 is the least significant bit
Bit 0 is the least significant bit
Worked example
0x8423 = 33827: bits 0, 1, 5, 10 and 15 are on. On many drives bit 15 of the status word signals a fault or alarm, so check the drive manual for the bit meanings.
Key insight: when a drive or device sends a negative number, it is usually just a 16 bit word with bit 15 set read as a signed integer; the bit pattern is what matters.
Advertisement
Frequently Asked Questions
How do I find which bits are set in a word?
Convert the value to binary; each 1 is a set bit, counting from bit 0 on the right.
Why is my status word negative?
Bit 15 is set and the PLC reads the word as a signed integer.
What does 0x0001 mean?
Only bit 0 is set.
You May Also Like
Learn more on the blog
Introduction to number systems
A practical, field focused guide on instrumentationblog.in that explains the theory behind this calculator and how engineers apply it on real plants.
Read Full ArticleMore PLC Digital Signal Calculators
PLC Analog Scaling CalculatorRaw to engineering, Engineering to rawADC Resolution Calculator8 to 24 bit, LSB sizeEncoder Pulse to RPM and Speed CalculatorHz to RPM, PPRPLC Timer Preset CalculatorTON and TOF, Time baseTime Proportioning Output CalculatorPID to digital output, Cycle timePLC Scan and Response Time CalculatorScan time, Input filterPLC Analog Input Digital Filter CalculatorFirst order filter, Filter factor αBCD to Decimal Converter for PLCsPacked BCD, Thumbwheel switchesGray Code Converter for Absolute EncodersGray code, Absolute encoderPLC I/O Count and Module CalculatorI/O list, Spare capacityPLC Setpoint Ramp Rate CalculatorSetpoint ramp, Increment per scanBinary, Hex and Decimal Converter16 and 32 bit register view
More Calculator Categories
Temperature Measurement26 live toolsInstrumentation Signal7 live toolsFlow Measurement30 live toolsLevel Measurement24 live toolsPressure Measurement24 live toolsControl Valve11 live toolsCalibration10 live toolsSafety and SIL10 live toolsAnalytical12 live toolsElectrical37 live toolsElectronics35 live toolsUnit Converters76 converters, 700+ units