Topology Options
- Updated2025-06-30
- 4 minute(s) read
Learn about the recommended topology options—line, ring, and star—land the advantages and disadvantages of each topology to choose the best option for your configuration.
For more information about designing Ethernet measurement systems for synchronization, refer to Designing Distributed TSN Ethernet-Based Measurement Systems.
Line Topology
In a line topology, also known as daisy-chaining or bus topology, the host communicates directly with all nodes through one bus line. A standard Ethernet device or switch can be added to the end of the chain if desired and used as normal. Be aware that these devices will compete for network bandwidth with the FieldDAQ device. A reliable system design requires awareness of the bandwidth consumed by each device during operations. This topology offers no redundant links.
Advantages:
- Simple and inexpensive installation, expansion, and troubleshooting
- Ideal for low number of nodes. NI recommends a maximum of 15 nodes.
- No external switch needed
- Can cover long distances
Disadvantages:
- Any unpowered nodes and/or node failure disrupts network communication
- Addition or removal of any node disrupts network communication
- Failure of any Ethernet cable and/or improper cable termination disrupts network communication
- Network performance and synchronization affected when node count exceeds 15. Consider the star topology for systems that require a greater number of nodes.
Ring Topology
In a ring topology, the host communicates with all nodes through the most effective path. You must use an external switch in a ring topology. You must configure the network properly with a recommended external switch before creating redundant links in the network. Refer to External Switch Requirements for information about what to look for in an external switch.
Advantages:
- Failure of any single Ethernet cable does not disrupt network communication
- Additional nodes or heavier network traffic affects network performance less than the line topology
- Simple installation
- Ideal for a local networking solution
Disadvantages:
- Network traffic patterns can make troubleshooting difficult
- Requires an external switch
Star Topology
In a star topology, the host communicates directly with each node through the external switch. You must use an external switch in a star topology; for network synchronization, you must use an external IEEE 802.1AS switch. Redundant links are recommended, but optional, in this topology. You must configure the network properly with a recommended external switch before creating redundant links in the network. Refer to External Switch Requirements for information about what to look for in an external IEEE 802.1AS switch.
Advantages:
- Unpowered nodes and/or node failure does not disrupt network communication with other nodes
- Failure of any single Ethernet cable does not disrupt network communication when you have a redundant link
- Additional nodes or heavier network traffic affects network performance less than the other topologies
- Simple installation, expansion, and troubleshooting
Disadvantages:
- Most costly of the recommended topologies
- Requires an external switch (external IEEE 802.1AS switch for network synchronization)
- Covers the least distance
Related Information
- Designing Distributed TSN Ethernet-Based Measurement Systems
- Power Connectors and Wiring
- External Switch Requirements
To meet the minimum requirements for successful operation with FieldDAQ devices, any switch directly connected to the FieldDAQ device should be compliant with IEEE 802.1Q bridges and bridged networks.