|Excel Developer Reference|
expression A variable that represents a WorksheetFunction object.
|Arg1||Required||Variant||The binary number you want to convert. Number cannot contain more than 10 characters (10 bits). The most significant bit of number is the sign bit. The remaining 9 bits are magnitude bits. Negative numbers are represented using two's-complement notation.|
If number is not a valid binary number, or if number contains more than 10 characters (10 bits), Bin2Dec generates an error value.