When embarking on a quest to outfit your environment with a PTZ camera workflow, the countless choices of cameras and related gear can be daunting. If you’re unfamiliar with the different methods to remotely control and connect the cameras to different pieces of equipment, it helps to understand all the protocols and connection types involved in PTZ camera workflows.
There are three main connectivity buckets for PTZ cameras that you will come across in your PTZ camera journey:
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Video Transmission Methods
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Control Types
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Power Methods
Video Transmission Methods
There are three main output methods that PTZ cameras utilize to specific types of equipment: direct video output, IP transmission, and HDBaseT transmission.
Direct Video Output
The direct output method is for shorter runs, when your cameras are close to a switch or computer. The limitations of these methods are that they have short cable distances and would require additional equipment to extend your cameras farther from a controller and video switcher. Many cameras on the market include more than one of these methods, so you can choose your methods later, or combine methods for simultaneous output.
HDMI - Maximum cable length: 25’
HDMI supports high-definition video and utilizes the highest bandwidth. It can also carry embedded audio and is common among most PTZ cameras and controllers. It can also be limited to video only, it does not carry control data, and it is limited to very short cable runs.
SDI - Maximum cable length: 400’
SDI can carry high-definition video up to 8K over 12G-SDI, and there are multiple standards such as 6G-SDI, 3G-SDI, HD-SDI, and SD-SDI for compatibility with a wide range of systems. It is most popular in broadcast environments. It also supports embedded audio, but unlike HDMI it can carry data for broadcast such as tally and genlock sync. SDI cabling also has a longer reach than HDMI, and transport distance depends on resolution and bandwidth.
Composite - Maximum cable length: 300’
Composite connectors are SDI or RCA connections that allow compatibility with older equipment. Composite is video only and doesn’t support embedded audio, and it only supports lower resolutions.
USB - Maximum cable length: 10’
USB is a common output for web camera use and is compatible with most computer operating systems. However, USB often does not support higher resolutions and it is limited to short cable runs and direct computer connections.
(Note: Maximum cable lengths are approximate and based on the use of highest-quality cables.)
IP Transmission
IP transmission is the ideal method for long-distance transmission, because IP is fast and cheap to scale and uses common, existing network switches and Internet-compatible hardware. When transmitting video over IP, bandwidth is one of the biggest challenges where more is always better. These protocols are common, fast, have no distance limits, and scale well, but some have security limitations.
IP
“Internet Protocol” (IP) is the standard network protocol that carries data of all types across networks around the globe. A good number of PTZ camera brands now support direct IP streaming via various protocols, such as RTSP, SRT, RTP, and others, which are standard streaming protocols used by web services such as YouTube and many proprietary streaming sites. Connector types include RJ45 and wireless.
NDI
“Network Device Interface” (NDI) is an IP protocol created by NewTek (now Vizrt) for high-quality, live broadcast IP networks. NDI is a widely used proprietary protocol with a software toolset that makes it easy to monitor, switch, power, and control cameras and broadcast equipment over any IP network using a single Ethernet cable. NDI requires a great deal of bandwidth since the streams are high quality, so NDI|HX (NDI high efficiency) streaming codecs were created to compress video, audio, and data into low-latency streams over slower networks. NDI networks make it easy to scale by just adding an NDI-enabled device onto the network, and it shows up ready to work.
Dante AV-H
Dante is a network protocol developed to connect audio devices over IP networks, and it has now expanded into Dante AV-H, a video and audio transport similar to NDI. Because NDI is more widespread in broadcasting, there are more tools and compatible devices available, but Dante AV-H is growing its compatibility reach. It is especially helpful when you already own Dante-compatible audio devices such as mixers and software and wish to add video devices to your network.
SMPTE 2110
SMPTE 2110 is another rich IP video and audio transport protocol that primarily transports high-quality, uncompressed video for standard broadcast networks. It is designed to work with standard broadcast facility equipment to transport highly reliable live signals over a closed, high-bandwidth network. SMPTE 2110 is scalable, versatile, and reliable, and is generally utilized for live television in news, events, and sports broadcasting. It has now been adopted by many manufacturers such as Blackmagic Design, AJA, LiveU, and Panasonic for connectivity and camera support.
ONVIF
When you have IP applications, there are always open-source options available. ONVIF (Open Network Video Interface Forum) is an IP-based open standard developed for security/surveillance cameras that utilizes different protocols to communicate with cameras, such as HTTP and RTSP, to make sure cameras and control gear communicate efficiently. Many PTZ cameras support ONVIF, however it is important to ensure compatibility with ONVIF software and other devices as open-source workflows can be tricky from brand to brand, and in some cases more advanced features can be difficult to program.
HDBaseT Transmission
HDBaseT is a very stable connection that can transmit just about any type of high-definition video using category cable over long distances, and it allows you to transmit different types of control data. It is a great idea when you don’t have an Ethernet network and your cameras just need a longer cable run to your controller. HDBaseT extenders can be used to extend your video, audio, and control data hundreds of feet away.
Fiber Transmission
Using fiber optics is an advanced way of transmitting video and data over extremely long distances, and it can be used for large venues, arenas, and connecting cameras in multi-room, multi-floor configurations. Fiber optic cable is an efficient way of transporting data using cable made from glass fibers and data is transmitted as light pulses.
Some cameras feature fiber module ports to transmit directly from a camera, but most cameras would have to be run through a fiber optic converter or fiber-enabled switcher that converts your IP, HDMI, SDI, or other data signal and transports it across long distances. Depending on what range you need, you’d have to decide between different types of fiber modules and amplification equipment. For example, single-mode fiber optic cable can transport lossless data over 100 miles away.
Control Protocols
When you have your video transport method in place, you’ll also need to transmit the actual data to control your cameras. This includes data commands such as pan (how far, what speed), tilt (what angle), and zoom (how far to zoom in, speed), and other settings such as iris, focus, and more.
IP Control Protocols
There are multiple protocols that can be transmitted over IP connections along with the video to control PTZ cameras:
VISCA-over-IP
VISCA originated as a serial control protocol created by Sony that delivers commands to PTZ cameras, and it has become a more open and adaptable protocol that can be transported over IP. Cameras that support VISCA commands and have IP connectivity can easily be controlled via a compatible IP controller that supports VISCA-over-IP commands.
IP Cloud Control
Some PTZ camera companies provide proprietary control from anywhere in the world using a web-based or IP controller. Companies such as PTZOptics with its cloud service called HIVE and BirdDog with its Cloud Connect services that connect operators via IP allowing configuration, preset storage, preview, recording, switching, and camera control from the cloud.
Canon XC
Similar to cloud control options, Canon has developed its own IP protocol that supports its cameras and controllers called the XC (crossover) protocol. It allows operators to connect to supported Canon PTZ cameras over the Internet to control them via a standard HTTP/HTTPS protocol.
NDI and Dante AV-H
Both NDI and Dante AV-H can also transmit camera control data alongside video streams for a fast, streamlined, scalable setup.
Serial Control Transport Methods
Serial control is an older but stable method of controlling PTZ cameras, providing point-to-point, long-throw connections that carry control data to your cameras, which is great for when you don’t have an IP network in your location.
Though it is a stable way to send controls to your cameras, it supports shorter cable extensions than IP and requires fixed installations. Compatibility can become an issue with newer equipment, and while some serial setups support daisy-chaining to control multiple cameras from a single controller, scaling is limited. Additional repeater and extender hardware may be needed to extend to greater cable lengths.
These serial transport methods utilize several different physical connector types, including DIN, D-Sub, terminal block (phoenix connector), and RJ45:
RS-232
RS-232 uses bidirectional communication but has only approximately 50’ of reach. It is the most common of the protocols because support for it on controllers and cameras is ubiquitous.
RS-422
The newer RS-422 method is more reliable than RS-232 with greater bandwidth, a richer command set, and a reach of up to 4000’, but it relies on unidirectional communication.
RS-485
Some older signaling protocols rely on RS-485 for bidirectional communication, such as Pelco-D and Pelco-P, but its reach is the shortest of the three connection types.
Serial Control Protocols
There are multiple serial protocols to choose from that will transport control data over the above serial connections to the camera:
VISCA (Video System Control Architecture)
VISCA was invented by Sony to control peripherals, and it has developed into the most commonly used PTZ/robotic camera control protocol. There is a newer version of VISCA that operates over IP, but VISCA started as a stable serial protocol that works over an RS-232 or RS-422 connection.
Pelco
The Pelco control protocol was originally designed for surveillance camera systems, and it is still supported to control PTZ cameras for a wide range of applications. Pelco offers fast, accurate camera movement but it is not easily scalable as it relies on a fixed cable infrastructure.
Pelco-D is older and uses ascii commands, a very simple command language. It requires direct cabling and does not have long range.
Pelco-P is newer and uses digital commands. Both Pelco-P and Pelco-D operate exclusively over RS-485, so your controller would need to support the connection and protocol for compatibility.
Other Control Protocols
There are a few additional methods can used to control PTZ cameras:
IR / RF
The remote controllers that come with the camera most commonly utilize infrared (IR), but they can also use radio frequency (RF) signaling, if supported by the camera. RF signals allow you to control your cameras remotely from longer distances than IR, as well as through obstacles like walls. The remotes provide simple camera select buttons, basic configuration, basic camera controls, and power.
UVC
When using a PTZ camera in web camera mode via USB, computers with supported software can utilize UVC (USB video class) to control some of the camera’s functions.
Power Methods
The final terminology that is helpful to understand when setting up PTZ environments is remote power. Since PTZ cameras are so easy to control from long distances, they are often installed in hard-to-reach places, and the power adapter that is often included with the camera may not be practical.
This is where power-over-cable (PoC) comes in. An RJ45 cable can carry data as well as power, so it is common to be able to power your camera with them while utilizing Ethernet (PoE) or HDBaseT (PoH) to deliver your video, so you can cut down on messy cabling or costly electrical upgrades.
For more information about designing your PTZ camera setup, feel free to give us a call, start a chat, or come visit us at the NYC SuperStore.
