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National Instruments Corporation
13
TBX-1329 Installation Guide
Specifications
All specifications are typical at 25 °C unless otherwise specified.
Electrical
Compatible modules
SCXI-1120/D .................................. 8 input channels
SCXI-1121 ...................................... 4 input channels and
4 excitation output channels
1
SCXI-1125 ...................................... 8 input channels
SCXI-1126 ...................................... 8 input channels
Coupling
DC or AC (selectable on a per-channel basis using slide switches)
2
AC coupling circuitry
Corner frequency (–3 dB)........ 0.072 Hz
DC-blocking capacity .............. ±250 VDC
Input impedance (minimum)
Between CH+ or CH–
terminals ........................... 2 M
Ω
Between CH+ or CH–
terminal and ground.......... 1 M
Ω
Current-receiver resistors
Resistors included ........................... none
Resistor sockets............................... 8 pairs
Maximum current ........................... ±20 mA
Maximum working voltage ( common – mode)
Channel to ground........................... Each channel must remain within
300 V
rms
or ±300 VDC of ground
Channel to channel.......................... Each channel must remain within
300 V
rms
or ±300 VDC of the
voltage applied to any other
channel
1
You must configure the excitation output channels for DC coupling.
2
In instrumentation terminology,
DC coupling
means that both DC and AC signals are passed.
AC coupling
means that
DC signals are blocked and AC signals are passed.
