Instruction manual

Designing and Planning an M2150 System
Access Control Design Guide 31
Cable Supervision
Determine the level of cable supervision required for cables to door monitors, exit-request buttons and
monitor points. This allows short-circuit, open-circuit and tamper conditions to be detected, depending on
the termination resistors added to the end of the cable (i.e. as near as possible to the monitor-point
contact, etc.). The SMS software can generate an alarm or event for any cable fault or tamper condition.
There are two-state, three-state, four-state and six-state supervision levels, as described next. The level of
supervision can be different for each contact used, and must be configured in the Install screens of the
SMS software.
Note: Monitor points connected to an ENVS can use only two-state supervision.
Two-State Supervision
The term "two-state supervision" means that the cable is not monitored for faults. No additional resistors
are used at the end of the cables, as shown in Figure 2-5.
Figure 2-5: Two-State Supervision
Three-State Supervision
Three-state supervision uses the cable termination shown in Figure 2-6. If three-state supervision is used
and the contact is normally open, only an open circuit on the cable can be detected. If the contact is
normally closed, only a short-circuit can be detected.
Figure 2-6: Three-State Supervision
Four-State Supervision
Four-state supervision uses the cable termination shown in Figure 2-7. In the case of four-state
supervision, both short-circuits and open-circuits on the cable can be detected.
Figure 2-7: Four-State Supervision