In an unsupervised circuit, a cut wire on a sensor wired normally open or a shorted wire on a sensor wired normally closed is not detected as alarm triggers. Supervision enables the Verkada BP41 alarm panel to detect these events and trigger a notification or alarm.
Supervision types
There are 2 types of supervision supported by the BP41 alarm panel:
Single End of Line Resistor (EOLR) (1 resistor)
Double EOLR (2 resistors)
These 2 types of supervision can be applied to sensors wired normally open (NO) or normally closed (NC). Reference resistance values for each type are shown below.
Single EOLR supervision (1000Ω resistors)
Resistance | Normally Closed (NC) | Normally Open (NO) |
0 Ω | Shorted circuit; trouble condition | Shorted circuit or closed event; alarm activated |
1000Ω | Normal state | Normal state |
Infinite Ω | Cut wire or open event; alarm activated | Cut wire; trouble condition |
Double EOLR supervision
Resistance | Normally Closed (NC) | Normally Open (NO) |
0 Ω | Shorted circuit; trouble condition | Shorted circuit; trouble condition |
1000Ω | Normal state | Closed event; alarm activated |
2000Ω | Open event; alarm activated | Normal state |
Infinite Ω | Cut wire; trouble condition | Cut wire; trouble condition |
Wire EOLRs to your BP41 alarm panel
In both circumstances, the resistors are installed at the end of the circuit, as close to the sensor as possible, because installing EOL resistors at the panel inhibits the purpose of supervision.
Single EOLR
Double EOL
Need more help? Contact Verkada Support.