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How to Connect a Siren to a Security Camera System

A great feature of CCTV Camera World’s security camera systems is the ability to add an external siren to the DVR or NVR. It is possible to connect a siren to our recorders that have an alarm input/output panel on the back. An external siren can alert a homeowner or business of potential intruders while also letting intruders know they have been spotted and alerted neighbors. In this article we show how to wire a siren correctly into our security camera systems and enable the correct settings.


Disclaimer: Sirens produce very loud sounds and can cause ear damage. If you are using a siren indoors please wear ear protection to avoid potential hearing loss or tinnitus as a result of a siren sounding off.

Required Hardware

  1. NVR or DVR with alarm input and output block on the back - a lot of recorders do not have it - if you want to use a siren make sure the recorder has the alarm block - check the specs table on our website
    1. Many recorders do not offer an alarm i/o block. If you want to use a siren make sure the recorder has the alarm block - check the specs table on our website
    2. Make sure you haven’t thrown away or discarded the green alarm block that is included in the accessories box. Replacements are hard to find.
  2. CAT5e full copper wire - To get a good connection with full contact and for the best transmission distance
  3. 6-12V DC powered Siren
  4. 12V DC power supply
  5. One male power terminal
  6. Two female power terminals

How to wire a siren to an NVR or DVR

Proper physical connection is key to the success of the siren working with the recorder in the security camera system. The stepwise guide below shows how to properly connect the bare wire leads on the siren to the alarm block on the recorder with easy to use connectors.

Step 1. Wiring the Siren to an Alarm Block

Step 1a. Locate the green alarm block that is in the accessories box for the recorder. This is the alarm terminal block.

pic of a terminal block

Do not confuse the alarm block with the RS485 connection which is for Pan Tilt Zoom Cameras (PTZ). This is not the alarm block.

rs485 connection on back of recorder

Step 1b. The block or the slots that the block fits into will be labeled with various codes - NO1, C1, ⏚(Ground)

  • If the recorder has multiple NO or C use the same number for the siren and power supply

Here’s what the alarm block look like on our most popular 8 channel and 16 channel NVRs:

alarm block with annotations

Step 1c. Wire the leads on the siren’s pigtail into a female power terminal as shown in the picture below. The solid red color wire connects to the positive (+) side, and the ground wire (striped wire) terminates into the negative (-) slot. Make sure the leads are secured to the connector and there is no excess wire protruding from the connector that may cause a short.

siren with wired terminal

Step 1d. Wire a male power terminal using a twisted pair of CAT5e or CAT6 wire leads to the C1 and ground (⏚) slots on the green terminal block. You can use up to 100ft of 24awg wire found in CAT5e cable, and choose any two color leads. It does not matter which color is used for the leads as long as the pairs are not confused and terminated incorrectly.

Strip the sheath of the Ethernet wire to expose some copper. Expose only enough copper to wire cleanly into the terminal. Excess wire can touch and short circuit the siren and recorder.

Wire the striped color wire into the positive (+) slot of the male terminal.

Wire the solid wire into the negative (-) slot of the male terminal.

alarm block with male terminal

Step 1e. Connect the male and female terminals to finish wiring the siren

wired siren

Step 2. Providing power to the siren through the alarm block

Disclaimer: Sirens produce very loud sounds and can cause ear damage. If you are using a siren indoors please wear ear protection to avoid potential hearing loss or tinnitus as a result of a siren sounding off.

Power is provided to the siren by relaying it though the Alarm I/O block. The wiring setup is similar to what we show in the section above, however we use a female terminal for a safer wiring setup. 12V DC power adapters come with a male power terminal.

2a. Wire a female power terminal using a separate pair of Ethernet wire leads. The leads should be a different color from what is used in the section above to avoid confusion. We like to use a solid and striped wire pair.

Strip the casing of the Ethernet wire to expose some copper. Expose only enough copper to wire cleanly into the terminal. Excess wire can touch and short circuit the siren and recorder.

Wire the striped wire into the positive(+) slot of the terminal.

Wire the solid color wire into the negative(-) slot of the terminal.

2b. Wire the terminal wires into the alarm block.

The positive (+) striped wire goes into the NO1 slot on the alarm block

The negative (-) solid wire goes into the ground (⏚)

alarm block with siren power terminal

2c. Connect a 12V DC power supply to the female power terminal.

The siren should now receive power from the alarm terminal on the recorder and if the Alarm Out settings are enabled the siren will sound.

siren with power supply wired to nvr alarm block

How to enable alarm out setting on an NVR or DVR

To have the siren sound off from the system it needs some event triggers and settings to be enabled on the security cameras.

Step 3. Set up Motion Detection, Smart Detection, or an external alarm

The first step to setting up alarm out settings is to enable some type of event detection on the security cameras that would activate the siren. There are multiple types of events that can activate the siren depending on the type of security camera system you have purchased, which include:

  • Video based motion detection
  • Smart Detection using video analytics
  • External alarm

For each type of event/trigger there is a setting called “Alarm Out” that can be found in the GUI interface of the DVR or NVR.

To learn how to configure individual detection settings refer to the guides below.

System Guide - Configuring Motion Detection Recording

Knowledge Base - Smart Detection Features

Knowledge Base - Adding an External PIR Alarm

Enable the Alarm Out setting for the trigger that corresponds with the alarm number the siren is wired into. CO1 is #1, CO2 is #2, and so on and so forth. Apply and save the settings.

Below is a screenshot of how we have the alarm output enabled on motion detection.

enabling alarm output on motion detection

Step 4. Enable and setup Alarm Output settings

Step 4a. From the main menu click the Alarm interface button. It has a Red alarm icon.

alarm from main menu g2

Step 4b. On the left hand menu click the Alarm Output submenu.

Step 4c. Under Alarm Type select Auto for the Alarm # that the siren is wired into.

Step 4d. Click Apply to save the settings.

alarm output enable g2

Matt Rossi is a Technical Support Manager at CCTV Camera World, a leading CCTV Camera distributor located in Buffalo, NY. He is a technical support expert for everything video surveillance related.

 

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