Siemens 
D12-52 Operating And Installation Instruction page 36

Signal
Start the signal mode
1. Set to Off"
4. 1 step to right
Set volume for...
6. button signals*
36
The acoustic signal indicates:
- that the additional functions (buttons) have been
switched on or off,
- individual programme statuses (e.g. start of
programme, end of programme), operating errors
and faults.
2.1 step to right
5. release and find the
nuber from 0 to 4
or 6.1 step to right
q After setting, turn the programme selector to
= Off", the volume of signal is stored.
* If required, set repeatedly.
3. keep selected and
7. Information signals*