Brother HL-2400C Series User Manual page 51

USER'S GUIDE
3–2
Notes
When you use the automatic emulation selection, note the following:

Once the emulation is automatically changed, it is not changed again
for a short period of time. This time period is called "Time Out" and it
can be set with the Emulation button. The factory setting is 5
seconds.

The EPSON or IBM emulation mode priority must be selected, as the
printer cannot distinguish between them. Since the factory setting is
the EPSON emulation mode, you might need to select the IBM
emulation mode with the Emulation button when you need to use
this emulation..

Try this function with your application software or network server. If
the function does not work properly, select the required emulation
mode manually using the printer panel buttons or use emulation
selection commands from your software.