What is the difference between Broadcast, Unicast and Multicast traffic and what are the required IP Settings
sACN is generally used in Multicast. Art-Net is generally used in Broadcast or Unicast.
This article covers Lighting Control Systems that transmit Unicast traffic over an Art-Net or sACN network
In a Unicast network the controller must know the static IP address of all devices to send traffic to. All devices need to be in the same IP range as the controller (ie. lighting console) and in Static IP mode. The receiving devices will only listen for traffic addressed to them. This allows for devices to ignore traffic that doesn't apply to them and allows for lower processor overhead on the device since it doesn't have to decode the entire packet to find out what it needs to do.
Caution
Broadcast Art-Net only works up to 15 Universes maximum with Quasar Science RR-R2 fixtures. If you broadcast a higher number of universes you will get inconsistent behavior from the fixtures and/or lag in their response. This is due to the Art-Net Broadcast storm overloading the input of the RR-R2. In these situations switch to Multicast SACN or Unicast Art-Net.
Note
All devices on a Unicast network must have static IP addresses assigned to them
Lighting control systems that transmit Broadcast traffic to over an Art-Net network
In a Broadcast setting the controller is sending out the entire Art-Net packet to every device on the network. Every device on network needs to decode the entire packet to find the information that applies to it. Advantages are that the user doesn't need to keep track of the IP addresses of devices on network.
Note
Devices on a broadcast network can have static IP addresses or use DHCP for their address assignments
The main disadvantage of Broadcast is that the processors on receiving fixtures/devices need to decode the entire Art-Net packet for all IP addresses in your subnet. This may overload weaker processor units causing erratic behavior on connected devices.
Lighting Control systems that transmit Multicast traffic over a sACN network
Multicast is a one-to-many data stream that is FAR MORE EFFECIENT of a protcol that Broadcast Art-Net. The controller on the network sends out the changes to the sACN packet over network and the sACN packets from the controller are divided into DMX universes, so devices on the network only listen for the universe that they are subscribed to.
The advantages are that you do not need to use or keep track of IP addresses for devices on network and bandwidth usage is much more efficient, allowing many universes of control over an unmanaged ethernet network.
When using Multicast sACN, devices on the network ignore their IP address settings and only listens to the Multicast IP address of the network. This is automatic which makes sACN plug & play for your lighting network.
Regardless of the type of system deployed Quasar Science recommends having a DHCP server on the network to distribute IP addresses to devices that are not configured with static IP addresses.