Loop supervision

If a resistor is placed at the end of a protection zone (at the last unit in the line), that zone becomes a supervised loop. A small amount of current can always be applied to that loop, allowing it to watch the wiring at all times. You can then program the system to give a warning light or audible alarm if it is tampered with during daytime hours. Supervising the loop is a security technique used to prevent internal tampering.

Terminal blocks with shared terminals

Figure34 . If the jumper wire is placed from the normally closed (NC) terminal to the NO terminal, as shown in the incorrect diagram, no alarm will sound. When wiring a tamper switch in series with the normally closed alarm loop, place the jumper or EOL device between the COM and T/NO terminals. The SureShot and some older Sharpshooter sensors have SPDT (single-pole double-throw) contacts in which the normally open (NO) and one of the tamper (TAMP) terminals are shared. When wiring a tamper switch in series with the alarm output in the normally closed configuration, be sure to wire the terminals as shown in the correct diagram in
Figure 34. Wiring terminal blocks with shared terminals IncorrectCorrect NC COM T/NO TAMP + – NC COM T/NO TAMP + –