Hex, Decimal, Binary and ASCII Converter
Convert PLC and Modbus register values between hex, decimal, signed decimal, binary and ASCII, with byte swap to check device byte order.
How It Works
Signed (two's complement): value − 65536 if above 32767
Byte swap: low byte × 256 + high byte
A Modbus register holds 16 bits. The same bits can mean an unsigned number, a signed number, two ASCII characters or packed status bits.
Worked example
0x41A2 = 16802 unsigned, binary 0100 0001 1010 0010, ASCII "A" and a non printable byte, byte swapped 0xA241 = 41537.
Frequently Asked Questions
How do I convert hex to decimal?
Multiply each hex digit by 16 to the power of its position and add; this tool does it instantly.
What is two's complement?
The standard way to store negative integers: values above 32767 represent negative numbers in 16 bit.
Why swap bytes?
Some devices send the low byte first; swapping shows the intended value.
Learn more on the blog
Introduction to number systems
A practical, field focused guide on instrumentationblog.in that explains the theory behind this tool and how engineers apply it on real plants.
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