NI NI-9853, Руководство пользователя

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Cable Requirements for EMC Compliance
Select and install cables for the NI-9853 in accordance with the following
requirements:
■
Install a clamp-on ferrite bead (NI part number 711849-01) on each end of
the cable for each channel that you are connecting to on the NI-9853.
■
Clamp-on ferrites must be connected to the cable as close to the module as
possible with a full turn as shown in the following figure. Placing the ferrite
elsewhere on the cable noticeably impairs its effectiveness.
Figure 1. Installing a Ferrite
Wiring the NI-9853
The NI-9853 has two 9-pin male D-Sub connectors that provide connections to a
CAN bus. Each port on the NI-9853 has pins for CAN_H and CAN_L, to which you
connect the CAN bus signals. Connect these signals using twisted-pair cable.
Each port has two common pins (COM) that are internally connected to the
module’s isolated reference and serve as the reference ground for CAN_H and
CAN_L. You can connect the CAN bus reference ground (sometimes referred to as
CAN_V-) to one or both COM pins. The port also has an optional shield pin, SHLD,
that you can connect to a shielded CAN cable. Connecting SHLD may improve signal
integrity and EMC performance in a noisy environment.
CAN0 of the NI-9853 is internally powered, and therefore requires no external power
supply. CAN1 requires an external power supply of +8 to +25 V to operate. Supply
power to the V
SUP
pin of CAN1 from the CAN bus.
Note
Although CAN0 of the NI-9853 does not require an external power
supply to operate, it can be connected to a powered CAN bus without
being damaged.
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NI-9853