Daisy Chain, Power Delivery & Power Pass-Through

Use the peripheral Thunderbolt 3 port on the LaCie 1big Dock for:

Direct connection to a device or display that is compatible with Thunderbolt 3 technology.
Daisy chaining devices and displays that are compatible with Thunderbolt 3 technology.
Connecting a laptop USB-C power adapter in order to pass-through power to a laptop connected to 1big Dock's host Thunderbolt 3 port.

How to daisy chain

The peripheral Thunderbolt 3 port on 1big Dock can be used to daisy chain compatible Thunderbolt 3 peripherals, such as hard drives and monitors. If you have another Thunderbolt 3 storage device, make certain to connect it to the daisy chain before adding compatible displays or USB 3.1 (USB-C) devices. See below for an example of the order of devices in a Thunderbolt 3 daisy chain.

Computer with a Thunderbolt 3 port.
LaCie 1big Dock (connected to computer via host Thunderbolt 3 port).
LaCie d2 Thunderbolt 3 (connected to 1big Dock's peripheral Thunderbolt 3 port).
Second LaCie d2 Thunderbolt 3 (connected to first d2 via Thunderbolt 3 port).
LaCie Rugged SSD (connected to second d2 via Thunderbolt 3 port).

USB 3.1 (USB-C) devices can terminate a Thunderbolt 3 daisy chain and should always be the last device. It must be connected to the secondary Thunderbolt 3 port on the preceding device. (The USB 3.1 device will not be recognized if connected to the preceding device’s USB-C port.)

Important cable info: When connecting 1big Dock's peripheral Thunderbolt 3 port to a compatible device, use cables specifically constructed to support Thunderbolt 3.

Daisy chain: power-saving mode

You can daisy chain Thunderbolt 3 devices even when 1big Dock is in power-saving mode. See Operation.

Power delivery and power pass-through

Your 1big Dock part number (P/N) determines your device's power delivery and power pass-through ratings. You can find the P/N on the label located on the bottom of the device.

Power delivery

1big Dock delivers power to your laptop's Thunderbolt port and to compatible devices connected to 1big Dock's peripheral port.

No device connected to peripheral port
Part number (P/N)	Host port	Peripheral port
P/N ending in 500	45W	-
P/N ending in 501	60W	-

Device connected to peripheral port
Part number (P/N)	Host port	Peripheral port
P/N ending in 500	30W	15W
P/N ending in 501	45W	15W

1big Dock must receive power via its power cable in order to deliver power to compatible devices.

LaCie is not responsible for devices that experience harm, damage, or malfunction when connected to LaCie 1big Dock.

Power pass-through

With power pass-through, you can attach a laptop's USB-C power supply to 1big Dock's peripheral Thunderbolt 3 port and let 1big Dock 'pass' power to the laptop.

Power pass-through
Part number (P/N)	Power pass-through	USB-C power supply connected to 1big Dock peripheral port	Power passed through to 1big Dock host port
P/N ending in 500	Available	> 60W and < 85W ≥ 85W	Up to 50W Up to 70W
P/N ending in 501	Not available	N/A	N/A

The power passed through may be limited by the host computer.