Measurement Computing USB-1096HFS, Руководство пользователя

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USB-1096HFS User's Guide Functional Details
3-7
Ground terminals
The USB-1096HFS has four identical ground (
GND
) connections - one ground terminal per digital port
group. The ground terminals provide a common ground for all USB-1096HFS functions.
Counter terminal
Connect an external TTL signal to the screw terminal labeled
CTR
. The internal counter increments when
the TTL level transitions from low to high. The counter can count frequencies of up to 1 MHz.
Daisy chaining additional modules to the USB-1096HFS
Daisy chained Measurement Advantage products connect to the USB bus through the high-speed hub on
the USB-1096HFS. You can daisy chain a maximum of four Measurement Advantage products to a
single USB 2.0 port or USB 1.1 port on your computer. Use the supplied cable or an equivalent cable
when daisy chaining Measurement Advantage products.
Depending on your load requirements, you may need to supply external power to each Measurement
Advantage product that you want to daisy chain. Refer to the next section "
Power limitations using
multiple USB-1096HFS devices " for more information.
Measurement Advantage products are USB 2.0 full-speed devices that provide a signaling bit rate of
12 Mb/s. The throughput rate is shared by all devices connected to the USB bus.
To daisy-chain two or more USB-1096HFS modules, follow the steps below. This procedure assumes
you already have one USB-1096HFS connected to a computer and to the external power source. The
USB-1096HFS already connected to the computer is referred to as the
connected module . The USB-
1096HFS you want to daisy-chain to the connected module is referred to as the new module.
1. Connect the
USB OUT
connector on the connected module to the
USB IN
connector on the new
module.
2. Connect the
POWER OUT
connector on the connected module to the
POWER IN
connector on
the new module.
3. For each additional module you want to add, repeat steps 1-2, with the module you just daisy
chained now being the
connected module.