VMS Help SET, TERMINAL, Qualifiers, /SPEED  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /SPEED=(input-rate,output-rate)

    Sets the baud rate at which the terminal receives and transmits
    data. If the input and output rates are the same, specify
    /SPEED=rate.

    Not all terminals support different input and output baud rates.
    For specific information on baud rates for your terminal, consult
    the manual for that terminal.

    The default transmission rates are installation dependent.

    The valid values for input and output baud rates are as follows:

     50       150       1800       4800       38400
     75       300       2000       7200       57600
    110       600       2400       9600       76800
    134      1200       3600      19200      115200