UP-3300 (serv.man6). UP3300 Handy Guide - Sharp EPOS Handy Guide. Page 13

The back up master system will allow for transfer of GLU and
Clerk codes on a network system if the master machine fails.

It is important that the correct files are allocated in the master and
back-up master machines.

If the files are not compatible there may be a communication
problem when performing a RECOVERY DECLARATION on the
BACK-UP machine.

The procedure to set up your system for back-up master is to
select the IRC set up from the service menu then select the
relevant terminal setting which will be satellites, then back-up
master then master.
You should select back up master exists on satellites and master
machines.

The master will then down load the program data as part of the
IRC set up.

It is important that you now carry out a recovery declaration on the
master machine, before operating on the system.

The back up system is now ready to function.

To test the back up system after performing the Recovery declare
carry out some transactions then turn off the power to the master
machine try then to start a new transaction on the satellite or back
up master the Power Off message should appear on your screen.
At this point go into Program two position on the back up master
and select Master Declare. You should now have a working
system.
When the Master is back in operation, Recovery Declaration would
be selected from the Back up master machine, this will send data
to update the Master machine to inform it that the system is back
to normal.