KMS Simplekey 4 - Loss of BUS Communications; Fail-Safe; Fail-Secure

Key Management Systems Ltd 30 | P a g e
Loss of BUS Communications
The Lock Controller can operate in two ways if communications are lost over the BUS,
Fail-Safe or Fail-Secure.
Both operations assume local 12V power remains.
KMS will default the Lock Controller to operate as Fail-Safe unless otherwise
requested. Requests must be made in writing by the approved installation contractor.
To comply with Secure By Design requirements (SBD) ALL doors must Fail-Secure.
Egress must always be provided by means of mechanical intervention, i.e. break glass,
RTE or auxiliary over-ride switch, typically the 12v side of the lock is broken via the
normally closed circuit.
The access control system must NOT be the only means of egress.
Fail-Safe - the Lock Controller will reverse its default lock state, typically dropping
the lock output and releasing the door.
Fail-Secure - the Lock Controller will retain its default lock state. For example,
power to lock devices such as magnets will remain locked.
Note: It is the installers’ responsibility to instruct KMS on default
lock operation as above.