What is supervision?
In an unsupervised circuit, a cut wire on a sensor wired normally open or a shorted wire on a sensor wired normally closed will not be detected as alarm triggers. Supervision enables the Verkada BP41 to detect these events and trigger a notification or alarm.
There are two types of supervision supported by the Verkada BP41:
Single EOL (one resistor)
Double EOL (two resistors)
These two 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 |
Wiring EOL resistors to your Verkada BP41
In both circumstances the resistors are installed at the end of the circuit as close to the sensor as possible – this is because installing EOL resistors at the panel will inhibit the purpose of supervision.
Single EOL resistor
Double EOL
