National Instruments 321906B-01 用户手册
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National Instruments Corporation
C-1
C
Customizing Your Card
This appendix describes options for customizing your NI 2501/2503 card.
Current-Loop Receivers
The NI 2501/2503 modules have sockets for transforming individual
channels to current-to-voltage converters. National Instruments offers
a process-current pack of four 249
channels to current-to-voltage converters. National Instruments offers
a process-current pack of four 249
Ω
, 0.1%, 5 ppm, 0.25 W resistors.
The reference designator format for the current-loop resistors is such that
for input channel x, the resistor is RCLx. For example, the resistor for
channel 14 is RCL14.
for input channel x, the resistor is RCLx. For example, the resistor for
channel 14 is RCL14.
Caution
Before installing the resistors in your module, make sure that no signals are
connected to your module front connector.
connected to your module front connector.
Before installing your module in the PXI chassis, you must install the
resistors by performing the following steps:
resistors by performing the following steps:
1.
Ground yourself via a grounding strap or a ground connected to
your PXI chassis. Properly grounding yourself prevents damage to
your PXI module from electrostatic discharge.
your PXI chassis. Properly grounding yourself prevents damage to
your PXI module from electrostatic discharge.
2.
Bend and trim the resistor lead as shown in Figure C-1. Be sure that
the resistor does not extend more than 0.5 in. above the surface of the
circuit board.
the resistor does not extend more than 0.5 in. above the surface of the
circuit board.
3.
Insert the resistor into the appropriate socket, labeled RCLx.
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