Input Ranges - National Instruments NI 435 Series User Manual

Ground-referenced
current source
Floating current source
Voltage here is
{–2.5V + [(R + R
resistance
Voltage here is
{–2.5V + [R
resistance
Voltage here is –2.5 V
Note: I is present on the NI 4351 only.
EX1
Caution Never apply voltages above these levels to the inputs. To prevent possible safety
hazards, the maximum voltage between any of the analog inputs and the computer ground
should never exceed ±42 VDC when the NI 435x is powered on and ±17 VDC when the
NI 435x is powered off.

Input Ranges

© National Instruments Corporation
0–20 mA
0–40 mA
0–20 mA
0–40 mA
) × 1 mA]}
rtd
RTD
× 1 mA]}
Resistance
Figure 2-11. Multiple Transducer Connections to Analog Channels
The NI 435x analog inputs are protected against damage from voltages
within ±42 VDC in all ranges when powered on and ±17 VDC when
powered off.
The NI 435x has six ranges for resistance measurements. These ranges are
25 kΩ, 50 kΩ, 100 kΩ, 150 kΩ, 300 kΩ, and 600 kΩ with the 25 µA
current source. These ranges correspond to the six input ranges available
for measuring DC voltages developed across resistors. These ranges are
±625 mV, ±1.25 V, ±2.5 V, ±3.75 V, ±7.5 V, and ±15 V. The NI 4351 for
R (User Supplied)
shunt
R (User Supplied)
shunt
in One Measurement Setup, Channels 6–9
2-23
Chapter 2 Operating the NI 435x Device
CH9+
Ground-Referencing: Off
Open-Thermocouple
Detection: Off
CH9–
CH8+
Ground-Referencing: On
Open-Thermocouple
Detection: Off
CH8–
I
EX1+
CH7+
Ground-Referencing: Off
Open-Thermocouple
Detection: Off
CH7–
CH6+
Ground-Referencing: Off
Open-Thermocouple
Detection: Off
CH6–
I
EX1–
NI 435x User Manual