Measurement Computing USB-1096HFS, Руководство пользователя

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USB-1096HFS User's Guide Functional Details
3-8
A daisy chain system is shown in Figure 3-4. Note that the last board in the chain is supplied with
external power.
USB port to
USB IN
USB OUT
to USB IN
POWER OUT to
POWER IN
USB OUT
to USB IN
CB-PWR - 9V3A supply
to POWER IN
CB
-
PWR
-
9V3A supply
to POWER IN
Figure 3-4. USB-1096HFS daisy-chain connections
Power limitations using multiple USB-1096HFS devices
When daisy chaining additional Measurement Advantage products to the USB-1096HFS, you must
ensure that you provide adequate power to each board that you connect. The USB-1096HFS is powered
with a 9 VDC nominal, 3.0 A external power supply.
Supply current
Running one USB-1096HFS at full load draws 2.6 A from the 3A supply. When using the USB-1096HFS
under full load conditions, you cannot daisy chain additional Measurement Advantage boards unless you
supply external power to each board in the chain.
If you are not sure how much current your application requires, we recommend that you provide separate
power to each Measurement Advantage product that you connect.
Voltage drop
A drop in voltage occurs with each board connected in a daisy chain system. The voltage drop between
the input of one Measurement Advantage product and the output of the board it is connected to is 0.5 V
maximum. Factor in this voltage drop when you configure a daisy chain system to ensure that adequate
power is provided to the last board in the chain. Always provide a separate power supply when the USB-
1096HFS is the last board in the chain.