user manual

3.2.1 USB-powered Hubs

These hubs draw all power from the host USB connector’s power pins. The

power is used for hub internal functions and for the hub’s ports. Each port of a

USB-powered hub must be capable of supplying at least 100 mA.

3.2.2 Self-powered Hubs

These hubs draw power from a source other than the host USB connector, with

exception that they may draw up to 100 mA from their upstream connection for

hub internal functions. The external power is used for hub internal functions and

for the hub’s ports. Each port of a self-powered hub must be capable of

supplying 500 mA.

3.2.3 Power Adaptors

Power adaptors, also referred to as auxiliary power packs, are required for some

self-powered hubs, and for DAQ modules that are powered from USB-powered

hubs. In addition, DAQ units will require the use of a power adaptor when used

with certain laptops.

When using a power adaptor with your DAQ system, be sure

to supply power (from the adaptor to the DAQ unit) before

connecting the USB cable. This allows the DAQ to inform the

host computer (upon connection of the USB cable) that the

unit requires minimal power from the computer.

Power adaptors for use with the DAQ have a current limit of 500 mA (min.) and

a voltage range of +7.5 to +12 Volts DC. These specifications are provided on the

end-face of the DAQ unit.

If the computer does not recognize the DAQ unit, make sure the computer’s USB

port is properly enabled and is in good working order. If the computer still fails

to recognize the DAQ unit, the use of an external 9v DC power adaptor may be

required.

The use of certain notebook computers may require the use

of a power adaptor with your DAQ unit.

Hardware Setup

3-2

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