Difference Between Active vs. Passive PoE

Difference Between Active vs. Passive PoE 

Power over Ethernet or PoE for short can be a new and potentially confusing term to a lot of people searching for security cameras. PoE connectivity simplifies cabling needed to connect a device by allowing power and data delivery over a single network cable such as CAT5e or CAT6. It makes it easy to connect devices such as IP security cameras, or office phones; a separate power supply or electrical outlet for each device is not needed. However, it is important to know the nuances about PoE equipment to avoid damaging your equipment. There are two types of PoE connections - active and passive. While one may think active is with power and passive is without power, that's not correct.

Active Power over Ethernet (PoE) uses an automatic negotiation handshake to safely deliver dynamic power levels based on device requirements, whereas passive PoE sends a constant, fixed voltage without any communication or safety check.

Active PoE

802.3af/at Compliant PoE - Good for IP cameras

Active PoE means that a device is rated to be 802.3af or 802.3at compliant. These are regulated specifications that require a device and power supply to do a “handshake” or verification. The PoE power supply tests the connection to the device and ensures that the power is compatible. If it isn’t, then the device simply will not power up, preventing any potential damage.

Active PoE Standards (IEEE 802.3)

The IEEE defines several Active PoE standards that determine how much power can safely be delivered.

Standard	Name	Max Power	Voltage Range
802.3af	PoE	Up to 15.5W	44–57V DC
802.3at	PoE+	Up to 30W	50–57V DC
802.3bt	PoE++	60–90W	52–57V DC

Passive PoE

Raw unnegotiated power - Bad for IP cameras

Passive PoE refers to any device that does not follow the 802.3af or 802.3at specifications. Passive PoE does not do any sort of power check so it simply supplies power regardless of what it is plugged into. This can damage any equipment not rated to accept the passive PoE power input. It is extremely important to understand the requirements and specifications of your equipment before plugging anything in.

Unfortunately, we see it too often that a customer damages their newly purchased IP security cameras when using a PoE switch such as a Unifi Switch that can output Passive PoE Power. If you choose to use your own PoE switch, we recommend use of reputable manufacturers such as Cisco, Netgear, or TP-Link that manufacture 802.3af/at compliant PoE hardware.

Calculating Passive PoE Power

If a device requires 12W and supports 12–30V, and you are using a 24V Passive PoE injector, you will need at least 0.5A to meet the power requirement:

24V x 0.5A = 12W.

Practical Limits for Passive PoE

·        24V Systems: Typically limited to about 50 metres due to higher voltage drop at lower voltages.

·        48V Systems: More efficient for longer runs, as higher voltage reduces the current needed for the same power, thereby minimizing heat loss (I²R).

·        Wiring: Passive PoE often uses Mode B, sending power over the "spare" pairs: pins 4/5 (+) and pins 7/8 (-)

Now question is How to access a PoE Security Camera from a Computer

We’re often asked how to modify an IP camera’s video settings once you already have it up and running on your NVR. This process can be difficult without any knowledge of computer networking or setting up a standalone IP camera. In this article we explain the technical details of taking a camera from the back of your NVR and connecting to it with either a direct connection or through your network.

The first steps include understanding how a camera and PoE NVR work together, noting the IP address the camera is configured to and finally physically removing the camera from the NVR.

After having a grasp on the basics and noting the IP address of your camera you can then proceed to the next steps. There are two ways that you can connect to a camera’s web interface:

·       The first is through a direct connection into your Windows desktop or laptop that has an ethernet port.

·       The second involves going over your computer network by configuring the camera to communicate on the network.

Be sure to note the IP address of the camera before disconnecting it from the NVR, you will need it later.

A) Direct connection between IP camera and Computer

The easiest way to access an IP camera is by connecting to it directly from a computer. This method requires you have the following:

1.   The IP address of your camera from the NVR registration page

2.   PoE Injector or 12VDC 1A Power Adapter. It is very important to use a CCTV Camera World approved device or you risk frying the camera due to incorrect voltage

3.   Two Ethernet cables (one if using a power adapter)

4.   Windows 11 pro based PC

1. Use a PoE injector to supply power and data

A PoE injector will have two ports, one labeled for PoE or P+D/Out (power and data) and one labeled LAN or Data/In. Connect the PoE injector to a power outlet. Connect an ethernet cable from your PC's network port to the Data/In on the PoE injector. Connect a second ethernet cable from the network camera's RJ45 network jack to the port labeled PoE or P+D/Out. To check if everything is connected properly refer to the lights on the PoE injector and the port on your computer. If you do not see any indication lights you may have a bad cable or do not have the wires connected properly.

2. Use a 12VDC 1A power adapter

A correct power adapter will have a label stating it is 12VDC 1000mA. Connect an ethernet cable from the camera directly to your computer’s ethernet port. A good way to check if the camera is receiving power and communicating with your computer is to look at the lights on your computer’s port. If you have no lights it is important to test that your cable and power supply work with another device.

3. Configure your PC's network port to communicate with the camera

For your computer to "speak" to your camera, you need to set its network port to the same IP address scheme as the camera. Before we disconnected the camera from the back of the NVR, we noted what the IP address of the camera was.

Login to your Windows PC, change your computer's ethernet adapter to communicate with the camera. Use the Network & Internet settings which contains an Ethernet section. Using the change adapter settings set an IP address for your computer that matches the network for the camera. If you do not know how to do this refer to the video above for this step.

4. Test the connection with the Ping command

After powering the camera and configuring your computer to talk with it, it is good practice to test the connection using the Ping command. Simply open the Command Prompt and type Ping with the address of the camera. In our case we used the following command: ping 10.1.1.65 -t press enter key.

5. Access the camera using Internet Explorer

It is important to use Internet Explorer as it is the most compatible browser for accessing security cameras. Type the IP address of your camera into the address bar in Internet Explorer. Some cameras may require initialization and it is recommended to uncheck the Easy4IP and auto-update options when proceeding through the prompts. The password can be admin, or may be printed on the label found on the box of the camera. Note: the customer is responsible for any password change beyond the defaults. There is no master reset password.

After successfully logging into the camera you need to install a plugin to view the camera. Click the link in the center of the page to download the plugin. Make sure to Run and do not save the plugin download. Internet Explorer will prompt you to allow the plugin to run. Once the plugin is installed, you will be required to log back into the camera. You should now see video from your camera and can modify the settings of the camera in the Setting tab within your browser. Make sure when you are done modifying your camera(s) that you change your network settings back to “Obtain IP address automatically” in your network settings, this is demonstrated in the video above.

B) Accessing the camera over your network

Besides direct connection to a computer, the other method to connect to a PoE security camera is over the network. This method requires the following pre-requisites:

1.   A home or business network with router

2.   Windows PC with ConfigTool installed

3.   PoE Injector or 12VDC 1A power adapter

4.   A network cable to connect to your router

5.   The IP address of your camera

1. Power the camera

You can use a PoE injector or 12V DC 1amp power adapter to power the camera and connect to your network router or switch. The process is simple. It is very important to use a CCTV Camera World approved device or you risk frying the camera due to incorrect voltage.

2. Connect the camera to your network router

Instead of connecting the camera directly to your computer, you will connect it to your network router so the computer can communicate with the camera over the network. When following this guide, it is important to connect the camera and computer to the same router or switch. We suggest using a hardwired connection between the computer and the router to prevent a situation where your WiFi network is different from the wired network. If you are knowledgeable about your network setup, feel free to use a WiFi laptop.

3. Use the ConfigTool to find the camera and change its IP address

Using the ConfigTool to find the camera on your network is fairly easy. It is imperative that you turn off any firewall or antivirus program on your computer that may prevent the program from sniffing your network.

4. Access the camera's web interface using Internet Explorer

The steps are similar to method A because the web interface will be the same regardless of how you connect to the camera.

Method for Identifying a PoE Power Supply Failure Caused by High Network Cable Resistance

If network cables can be removed from the switch at the local site, use below method to measure the resistance.

·        Measurement tool: Multimeter

·        Measurement contents and procedure: Use the multimeter to measure the DC resistance of each cable wire and take down the measured values as R1, R2,…R8.

·        Measurement results:

Network cable resistance:

R = (R1 + R2 + R3 + R6)/4 (when the switch uses the wires 1, 2, 3, and 6 to supply power.)

Or:

R = (R4 + R5 + R7 + R8)/4 (when the switch uses the wires 4, 5, 7, and 8 to supply power.)

Usually, the AC and PoE switch use wires 1, 2, 3, and 6 for power supply, and the PoE adapter uses wires 4, 5, 7, and 8 for power supply.

Key Takeaways

The primary difference between Active and Passive Power over Ethernet (PoE) is how they deliver power: Active PoE communicates with a device to ensure it is safe to power, while Passive PoE sends electricity immediately without checking compatibility.

Active PoE (The "Smart" Choice)

Active PoE is the industry standard for most modern business networks.

·        Intelligent Handshake: The power source (PSE) sends a low-voltage signal to detect if the connected device is PoE-compatible and determines exactly how much power it needs.

·        Protection: If you plug in a laptop or a non-PoE device, the switch detects it and sends only data, preventing electrical damage.

·        Common Standards:

o   PoE (802.3af): Up to 15.4W per port.

o   PoE+ (802.3at): Up to 30W per port.

o   PoE++ (802.3bt): Up to 60W or 100W for high-power devices.

Passive PoE (The "Always-On" Choice)

Passive PoE is common in specific setups like outdoor wireless bridges or legacy equipment.

·        No Communication: It does not check the device's needs; it simply pushes a fixed voltage over specific pins in the Ethernet cable.

·        High Risk: If you plug a device into a passive port that doesn't match its required voltage (e.g., 48V into a 24V device), it can cause permanent electrical failure.

·        Manual Matching: You must manually verify that your injector or switch matches the exact voltage and pinout required by your device.

Which should you choose?

·        Choose Active PoE for almost all standard office or home office uses (IP cameras, VoIP phones, modern Access Points) to ensure safety and future-proofing.

·        Choose Passive PoE only if you have specific legacy hardware or budget-constrained outdoor installations where you are certain the power specs match perfectly

How to Find Your Model's Requirements

1.   Check the Physical Label: Look for a sticker on the back or bottom of the device. It will often list "802.3af," "802.3at," or a specific voltage like "24V DC".

2.   Consult the Datasheet: Search for your model number + "technical specs" online. Look specifically for the "Power Method" field.

3.   Check the Box: If you still have the original packaging, the required PoE standard is usually printed on the side near the serial number.

 

How to add a microphone to an IP Camera

How to add a microphone to an IP Camera

Most security cameras that are outdoor rated do not come with built-in microphones to ensure that no water can leak in. This means that you must add an external security camera microphone to these cameras in order to record audio. CCTV Camera World carries microphones for indoor or outdoor cameras. Most IP security cameras with audio input capabilities have an RCA audio connector on their pigtail for connecting a microphone. Some dome IP cameras have a connection block on the inside of the dome. In either case, physically connecting and configuring external microphones to an IP security camera is easy as shown in this guide.

How to tell which camera you have?

In case you are unsure, here's a quick image to help you understand which type of audio connection your IP camera has.

Depending on whether your camera has a RCA or two-wire line in connection, please follow the appropriate section below.

1.   Connecting a microphone using RCA input

2.   Connecting a microphone using two-lead wire

3.   Enabling audio-input on the camera

 

 

 

Setup for IP Cameras with RCA Audio Input connectors

What's needed?

Here is what you need to connect a microphone to an IP camera that has RCA audio inputs:

1. Outdoor Microphone (sku 71891) or Indoor Microphone (sku 7100CC)
2. 12V DC 500mA Power Supply (sku 12V5MA)
   You can also use PoE Power Splitter (sku POE101D) with DC Power Splitter Cable (sku DC-PJJ)
3. RCA Male to RCA Male Adapter (sku RCA01)

How to connect a microphone to an IP camera that has RCA audio input

Below is a diagram of how to connect an external microphone to the RCA audio connector on an IP camera.

It is easy to connect a mic by following these easy to follow steps:

1. Connect the microphone to the RCA audio input on the camera's pigtail using a RCA Male to RCA Male connector
2. For longer runs between the camera and microphone you can use an RCA cable with male ends to connect the input and output.
3. Connect the power connector from the 12V DC Power Supply to the female power jack on the microphone.

Alternatively, you can also use a PoE Power Splitter with a 1-to-2 DC Power Splitter to use PoE power for the microphone and camera. Simply connect the PoE cable into the PoE splitter. Then split the power to the camera and microphone using the DC splitter. The data cable for the PoE splitter then connects to the camera for data.

After you have correctly wired the microphone to the camera you can continue to the rest of the article to find out how to enable the cameras audio input for listening and recording.

Setup for IP Cameras with Audio Line-in Input

Some IP security cameras include an internal audio line-in block or a two-wire lead that requires a two-lead connection for connecting a microphone. At first it may seem puzzling how a microphone with a RCA connection would connect to a two-wire input. As an example, in the section below we use a video balun, BNC to RCA connector, and two-lead wire to connect the microphone to the line-in block.

What's needed?

You will need the following items to connect a microphone to a camera with a line-in audio connection consisting of two-lead cabling.

1.   Outdoor Microphone - (sku 71891) or Indoor Microphone (sku 7100CC)

2.   12V DC 500mA Power Supply (sku 12V5MA)
You can also use PoE Power Splitter (sku POE101D) with DC Power Splitter Cable (sku DC-PJJ)

3.   Video Balun (sku VB2PHD)

4.   BNC Female to RCA Male Connector (sku BNCRCA02)

5.   Two-lead Wire for the balun

Best Practices for Using A Two-Way Audio Security Camera

Whether you have a security camera system for a home or business, the need for two-way audio interaction with talk-back capability may arise. CCTV Camera World offers solutions for both one-way and two-way audio. One-way audio is great for listening to sound originating from the location of a camera, but it will not allow interaction with a person at that location. To be able to interact with a person at the camera, the camera would have to have two-way talk capabilities, i.e. a speaker and microphone built-in similar to an intercom.

Two-Way Audio Setup With PoE NVR

Step 1) Connect cameras to NVR

In this guide, we will be using our security camera with two-way audio, sku IP3MPA.  It is a two-way audio IP camera that allows the user to not only listen-in, but also talk back to the person at the camera. These cameras are very easy to connect using the plug-and-play technology. In the video demonstration above we show how easy it is to connect our PoE IP cameras to our PoE NVRs. Simply connect the cables between the camera and the NVR. A single network cable transmits power and data to each camera from the NVR, and plug-and-play technology handles IP address configuration between the camera and NVR without user intervention.

Using a Web Browser for Two-Way Audio

Our camera systems allow the user to engage in two-way talk over the network by using Internet Explorer on a computer or by using our iOS and Android apps for both phones and tablets. First, we will demonstrate how to use the web portal called Web Service in our security systems. A Windows PC running Internet Explorer is required for two-way talk capability through the web browser. To be able to talk-back, you will need to make sure you have a headset or combination of microphone and speaker on your PC to listen and talk-back.

All DVRs and NVRs from CCTV Camera World are network devices and have their own IP address. You first need to connect your security camera system to your network by assigning the DVR/NVR an IP address that fits your network scheme. Once that is complete, you will be able to view your system from a computer or smartphone and use the two-way audio feature over the network. If you wish to view the system over the web when away from home, you will need to set port forwarding rules on your router's firewall to allow remote viewing from the internet.

Once your system is properly connected to your network and port forwarding rules have been created on your firewall, you will be able to engage in two-way audio communication using your smartphone, tablet, or PC from anywhere in the world where Internet is available.

Step 2) How to use two-way talk on Internet Explorer

1.   Open an Internet Explorer window on your Windows PC and type in either your NVR's IP address for local viewing, or external IP address for remote viewing.

2.   Type in your system's username and password, and select Login.

3.   Make sure audio is enabled in your two-way camera by going to Setup and Encode.

4.   Click the Audio Enable check boxes for both the Main and Sub Streams (if they are not already checked).

5.   Select OK to ensure your settings have been saved.

6.   Click the Preview tab to view your camera's live feed.

7.   Select the channel by clicking the quadrant containing the video feed. A green frame will appear around the video feed to distinguish the selected channel.

8.   Select the Speaker Icon in the top-right corner of the selected camera's video feed for one-way audio. This will allow you to hear audio that's taking place at the location of your camera.

9.   To talk back and send out audio through the camera's speaker, select the Microphone Icon in the top-right corner of the selected camera's video feed. You will need either a headset with microphone, or a combination of microphone and computer speakers to listen and talk back.

Now you will be able to listen and talk back to someone at the location of your camera. Note that you will be able to listen to camera audio feeds one at a time - you will not be able to listen to multiple audio feeds simultaneously. Multiple users can listen to one-way audio from a camera, but the talk back function is done by one user at a time.

If a computer is not available to view your two-way audio camera system, then proceed to the next section where we explain how to use two-way talk with a smartphone or tablet.

Two-Way Audio Interaction Using iOS or Android Phone/Tablet

A more convenient way of viewing you security camera system and engaging in two-way audio talk is through your mobile device. The App allows the user to hear incoming audio from the camera and uses the microphone from the phone to talk back, sending out audio through the camera's speaker.

Step 3) How to use Two-Way Talk with a Smartphone or Tablet

1.   First, Open the app (iDMSS) on your iPhone or Tablet (or gDMSS for Android devices).

2.   Select the Menu Icon in the top-left corner, and choose Device Manager.

3.   From here, select the Plus Sign in the top right corner,  Wired Device and then IP/Domain.

4.   Fill out the appropriate credentials of your NVR. You will need to create two entries - one for viewing at the location of your system using Wi-Fi, and second entry for when viewing remotely over the internet away from home. We have a tutorial on how to create entries for both local and remote viewing. After all credentials have been entered, select Start Live Preview.

5.   Select the camera channel you want to engage in two-way audio with by tapping the video feed from that camera, and then press the Speaker Icon. The speaker icon allows the user to  listen to incoming audio from the camera and talk-back sending out audio through the camera's speaker.

Briefly, here is what we did:

1.   Open the dome cover of the camera using the included hex-key tool. Do not use powered screwdrivers or drills or you will damage the dome.

2.   Connect the BNC Female to RCA Male connector to the balun.

3.   Connect the RCA Male tip to the RCA input on the microphone.

4.   Use the video balun to wire in the two lead wire, tighten the screw-downs for the wires.

1. Make sure that you remember the polarity for your wires. We suggest using Red for the positive wire, and Black/Striped for the ground/negative wire.
2. Having a bad connection or the wrong polarity will not record sound or have loud interference.

5.   Locate the small rubber insert next to the Audio/Alarm block and create a small hole for the wires.

6.   Slightly unscrew the screw-down for the Audio-In connector on the block. Insert the positive wire from the video balun and screw it down.

7.   Slightly unscrew the screw-down for the ground connector (GND). Insert the ground wire from the video balun and screw it down.

8.   Run the power cable for the microphone to the 12V DC power supply that is connected to a 220V AC power outlet. Connect the power supply to the microphone.

a)   Alternatively you can use a PoE splitter with a 1-to-2 DC power splitter.

b)   Connect the PoE cable for the camera to the PoE splitter. Then connect the PoE splitter to the 1-to-2 DC power splitter.

c)   Connect the camera and microphone to the DC power splitter connectors.

d)   Connect the RJ45 jack coming from the PoE splitter into the pigtail on the camera.

Once you finally have your camera and microphone connected you can continue to follow the rest of this guide to learn how to enable audio input on the camera.

How to enable audio recording on an IP camera

After everything is connected you must configure the camera to recognize and use the external microphone. This step is extremely important before trying to listen and record a camera. Do not assume that the camera is automatically recording audio when you plug the microphone in.

Using Internet Explorer to enable and modify audio settings

In the video below we show how to use Internet Explorer to login and modify the settings on an IP camera. This process requires knowing what the IP address of the camera is. After that it is as easy as logging in and going to the Settings page. Navigate to the Camera > Audio page. There you will find the audio settings for the camera. You can enable audio for Main-stream or Sub-stream, fine tune the volume settings, and enable the noise filter. Also if a camera has a built-in microphone you can set it to use the external microphone instead.