Description: Append a 'wait' command to the script. The set value of this object should be the maximum waiting time for the packet containing the content configured in the last expect command. Wait time is in units of milliseconds, and the maximum supported is 65535 ms. The 'wait ' characters will be automatically appended. Also a 'null terminator'(\0) will be automatically appended. The null terminator and the 'wait ' characters will be counted as characters in the script. When read, the return value has no significant meaning, but a 1 is always returned.