End-of-line
The term end-of-line refers to the termination point or the final point in a circuit or system. It is typically used to indicate the end of a communication or control line, where a device or component is connected.
In access control systems, end-of-line typically refers to the point where a sensor or detection device (e.g. contact sensor, request-to-exit device, motion detector) is connected to a control panel. For example, a contact sensor may be connected as part of such a line, and the control panel monitors the status of that line. If the line is tampered with or the circuit is broken (e.g., someone attempts to bypass the sensor), the control panel can detect the change in the line's status and initiate an appropriate response, such as activating an alarm or sending notifications to a security team.
Kisi can detect compromised wiring
The Kisi Controller Pro 2.0 inputs by default expect trivial electrical circuits to monitor the open-closed state of assigned doors. The circuit is either closed or open, and consequently returns a digital reading: 0 or 1. Most setups will follow this approach. However, sometimes detecting short circuits and cut wires is desired.
With a little more advanced contact sensor circuitry the controller can detect malfunctions of the wiring by measuring the voltage. This works by adding one or two resistors to the wiring circuit that will cause different voltage readings in different scenarios.
Required resistor types
To ensure proper functionality of the feature, please use the following types of resistors:
- R1: Main resistor - 2.2k Ohm
- R2: Second resistor - 1k Ohm
End-of-line (EOL) modes of operation
There are three types of end-of-line modus operandi:
- Single EOL - cut detection
- Single EOL - short detection
- Double EOL - cut and short detection
Below you find documentation for each of the types. The symbols have the following meanings:
- +D+: door
- +R1+: main resistor (we care about the resistance)
- +R2+: second resistor (we care about the resistance)
- +KC+: Kisi Controller input
- +CS+: contact sensor, e.g. Reed switch
- +S+: short
- +C+: cut
Both resistors must have a value > 0 in Ohms.
Single EOL - short detection
+----+
+----+----+------+ R1 +-----+
| KC | S +----+ |
+----+----+---+ |
| +--+ +--+ |
| | | | | |
+-+CS| D |CS+-+
| | | |
+--+ +--+
In this configuration, the end-of-line resistor is placed in series with the contact sensor, and that allows us to detect a short in the wiring.
Single EOL - cut detection
+-----<C>------------+
| |
| +---+ |
+----+-+ +--+ R1 +-----+
| KC | | +---+ |
+----+--------+ |
| +--+ +--+ |
| | | | | |
+-+CS| D |CS+-+
| | | |
+--+ +--+
In this configuration, the end-of-line resistor is placed in parallel with the contact sensor, and that allows us to detect a cut in the wiring.
Double EOL cut and short detection
+----+
+--+ R1 +------------+
| +----+ |
<C> |
| +---+ |
+----+-+ <S> +--+ R2 +------+
| KC | | +---+ |
+----+-------+ |
| +--+ +--+ |
| | | | | |
+-+CS| D |CS+-+
| | | |
+--+ +--+
In this configuration, two end-of-line resistors are placed in the circuit, in parallel and in series with the contact sensor. This allows us to detect if there is a short or a cut in the wiring.