If there are 32 IM in one BDU zone, need to use the Power supply-PC7H
Support one door station only ( new branch will issue soon)
If more than three BDUs are needed, should use the old rule to set the key value of the button
IM in one DBU zone: Normal IM Max.32, DX Max.8, DT47MG Max.12
Upgraded DT821/VD, DT821/M4, BDU are required for the above application