The get-device-offset command performs an inquiry read, typically used for non-intrusive inspection, while read-device-offset does a standard access that may trigger side-effects in the device. Note that not all device models support inquiry accesses.
Some devices, such as ones written in DML, provide a preferred byte endianness that data should be interpreted in. The command will use this endianness unless the -l or -b flags are used to select an alternate one.
Not all devices support accesses that span several registers or that accesses a register partially. (For DML 1.2 devices, such support must be enabled in the device when it is compiled. This limitation is planned to be removed in the next version of the language.)