a hexidecimal number in a string. Many JSON parser cannot handle 64-bit
integers, which is why we are not using a numerical data type. Each byte in
the string *must* be represented with 2 characters, e.g. `0x1` is `0x01` - the
- complete string must have an even number of characters.
+ complete string must have an even number of characters. The `0x` prefix is
+ optional.
### Diagnostic Messages
**id** - the CAN arbitration ID for the request.
-**mode** - the OBD-II mode of the request - 1 through 255 (1 through 9 are the
+**mode** - the OBD-II mode of the request - 0x1 through 0xff (1 through 9 are the
standardized modes and 0x22 is a common proprietary mode).
**pid** - (optional) the PID for the request, if applicable.
represented as a hexadecimal number in a string. Many JSON parser cannot
handle 64-bit integers, which is why we are not using a numerical data type.
Each byte in the string *must* be represented with 2 characters, e.g. `0x1`
- is `0x01` - the complete string must have an even number of characters.
+ is `0x01` - the complete string must have an even number of characters. The
+ `0x` prefix is optional.
**name** - (optional, defaults to nothing) A human readable, string name for
this request. If provided, the response will have a `name` field (much like a