Getting Started with Networks for ETC Systems
What is a network?
At its most basic, a network is a system of interconnected devices that share data.
The type of network used in ETC lighting systems is called a Local Area Network, or LAN.
What infrastructure is needed?
This is dependent upon your site and its needs; a stadium's network is going to be more complex than a high school theater's network. But essentially:
- Network switch: A device which connects multiple devices on a network. This is the communication hub of the network. Network switches can be managed, which means they have a configuration of settings, or unmanaged, these are simpler network switches that do not need configuration.
- How this differs in larger systems: more complex networks may have many switches connected to each other.
- Network devices: Computers, consoles, gateways, architectural and power control processors, wireless access points/routers, and more. These devices all communicate with each other via their connections to network switches.
- Signal path: Ethernet, which runs via Cat5 or Cat6 cabling and wireless (Wi-Fi)
- How this differs in larger systems: more complex networks often use fiber-optic cable to make connections over very long distances.
Networks are laid out using a star topology, or connection method. This means each device is connected directly to a network switch:
Example of an ETC lighting network:
Key elements to keep track of:
- How the network system is all connected: what plugs into which port on the network switch and what is wireless.
- Where network switch(es) is/ are located and how they are connected to each other (if using multiple.)
- If the network switches in the system are managed or unmanaged.
- IP address and subnet mask of each network device. Each numerical ID breaks down into four octets separated by dots. This breaks down as follows:
- IP address: Unique numerical ID for the specific network device
- Example: Ion Xe console's is 10.101.50.10, Sensor IQ's processor is 10.101.10.101
- Subnet mask: A numerical ID that divides a network into subgroups called "subnets."
- Example: 255.255.0.0. Think of this as defining:
- First octet: The country
- Second octet: The state/ providence
- Third octet: The zip/ postal code
- Four octet: The street address
- Example: 255.255.0.0. Think of this as defining:
- How IP addresses and subnet masks work together: Wherever there's a "255" in the subnet octet, device IP addresses need to match in order for the devices to talk to one another; wherever there is a "0", device IP address do not need to match.
- Example: On a network with a 255.255.0.0 subnet, Device A with an IP address of 10.101.101.1 and Device B with an IP address of 10.101.40.50 will be able to communicate, but Device C with an IP address of 10.200.101.50 will not be able to. To clarify:
- Device A 10.101.101.1/ 255.255.0.0 <--> Device B 10.101.40.50/ 255.255.0.0: can talk
- Device C 10.200.101.50/ 255.255.0.0 <-/-> Device A 10.101.101.1/ 255.255.0.0: can NOT talk
- Device C 10.200.101.50/ 255.255.0.0 <-/-> Device B 10.101.40.50/ 255.255.0.0: can NOT talk
- Sometimes you may see IP addresses and subnets notated as "IP address/ 16" or IP address/ 24".
- 16 = a subnet of 255.255.0.0
- 24 = a subnet of 255.255.255.0
- Example: On a network with a 255.255.0.0 subnet, Device A with an IP address of 10.101.101.1 and Device B with an IP address of 10.101.40.50 will be able to communicate, but Device C with an IP address of 10.200.101.50 will not be able to. To clarify:
- A typical ETC lighting network uses IP addresses starting with 10.101 and a subnet mask of 255.255.0.0.
- IP address: Unique numerical ID for the specific network device
Key system concepts:
- No duplicate IP addresses! As mentioned in the section above, every device on the network has to have an unique IP address. If there are devices with the same IP address his can cause an intermittent device connection, devices being disconnected from the network, or devices consistently rebooting (boot looping.)
- No network loops! As shown in the diagrams above, each device must have only one connection point to the switch; and when multiple network switches are being used, these must have only one connection point to each other. While devices having multiple paths to one another for redundancy may seem like a good idea, this can cause a network loop. A network loop can cause data to multiply and cycle endlessly. In turn, this can result in data being lost between devices, signal to degrade, and latency.