daisy-chain
Especially of a computer device, peripheral, or other component: to be capable of being connected with other components in sequence.
daisy-chain: linking devices in a single cable loop
To daisy-chain is to connect multiple devices or peripherals in a serial sequence along a single cable run, where each unit passes the signal onward to the next. The first device connects to the host controller or power source; the second device connects to the first; the third to the second; and so on. This differs from star topology, where each device connects independently back to a central hub or controller.
Daisy-chaining is common in older industrial and consumer electronics, particularly in SCSI (Small Computer System Interface) chains, FireWire (IEEE 1394) networks, and some legacy fieldbus systems. Each device in the chain must have both an input and an output connector for the signal to pass through. Termination is critical: the last device in the chain requires a terminator plug or resistor pack to prevent signal reflection that causes data corruption and communication failure.
When daisy-chaining works and when it fails
Daisy-chaining reduces cable clutter and can lower installation cost when devices are physically arranged in a line. However, the method has hard limits. Cable length accumulates, introducing signal degradation and latency. A break in any middle device or connection disrupts the entire chain downstream. Modern systems have largely moved away from daisy-chaining toward star topology or switched networks because they offer better fault isolation, easier troubleshooting, and support for higher data rates without signal integrity problems.
The term comes from the appearance of flowers linked in a string: a chain of daisies. Each flower is connected only to its neighbors, forming a linear sequence. Industrial adopters borrowed the metaphor because the topology visually resembles that simple garden arrangement, even though the electrical purpose is entirely different.
In modern industrial control, you will encounter daisy-chaining mainly in legacy systems, certain sensor arrays on single twisted-pair lines, and some specialized fieldbus implementations. New installations typically favor point-to-point wiring or network-based communication. Understanding daisy-chain architecture remains essential for maintaining and troubleshooting older equipment, particularly around SCSI disk arrays and industrial automation systems installed in the 1990s and 2000s.