SCXI-1305 Installation Guide
10
ni.com
SCXI-1140.......................................8 input channels,
one external clock signal
SCXI-1141/1142/1143 ....................8 input channels,
two clock signals
Coupling .................................................DC or AC
(selectable on a per-channel
basis using slide switches)
1
AC coupling circuitry
Corner frequency (–3 dB)................0.16 Hz
DC-rejection capacity......................±42 VDC
Input impedance (minimum)
Between CH+ and
CH– terminals ..........................2 M
Ω
Between CH+ or CH–
terminal and ground .................1 M
Ω
2
Maximum working voltage
( common-mode)
Channel to ground ...........................Each channel must remain within
±42 VDC of ground
Channel to channel ..........................Each channel must remain within
±42 VDC of the voltage applied
to any other channel
Field-wiring connectors
Signal connectors.............................8 female BNC connectors
Auxiliary connectors .......................1 female SMB connector
Signal connector spacing.................1.8 cm (0.75 in.)
Ground-referencing
You can configure the SCXI-1305 for use with either
ground-referenced or non-referenced (floating) signal sources on a
per-channel basis using slide switches. When a channel is configured
for use with a non-referenced (floating) signal source, CH– is
connected to analog ground through a 100 k
Ω
resistor.
1
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.
2
Does not apply to the SCXI-1120/D, SCXI-1121, SCXI-1125, or SCXI-1126.
