It is possible to lock out all the keys, including LOCAL, on the WT210/WT230 using a GPIB specific or controller specific command.
For the GPIB controller from National Instruments, the command is called LLO or Local Lock Out. This command will vary based on the type of controller board that is being used.
When you send a "*IDN?" query command to the WT210/WT230, the instrument will receive the command and turn to LOCAL mode, causing the LOCAL LED indicator to illuminate. Send the "LLO" command to lock out all keys on the instrument. To return to Local mode, send the command "GTL" (Go To Local).