SCXI-1503 Datasheet, PDF (1/5 Pages) National Instruments Corporation – SCXI 16-Channel RTD Module

SCXI 16-Channel RTD Module
NI SCXI-1503 NEW!
• 16 channels of voltage or
resistive inputs
• Ideally suited for 2-, 3-, and 4-wire
RTD and thermistor measurements
• Programmable gain settings per channel
• 5 Hz filter per channel
• 100 μA current excitation
• 333 kS/s maximum sampling rate
• NI-DAQmx driver software
simplifies configuration, scaling,
and measurements
Operating Systems
• Windows XP/2000/NT
Recommended Software
• LabVIEW
• LabWindows^™/CVI
• Measurement Studio
Other Compatible Software
• Visual Basic, C, C++
Measurement Services
Software (included)
• NI-DAQmx driver software
• Measurement & Automation Explorer
configuration utility
Calibration Certificate Included
Overview
Current Source Operation
The National Instruments SCXI-1503 RTD module provides 16 differential
input channels, 16 channels of 100 μA current excitation, and one
cold-junction (CJ) sensor channel. The NI SCXI-1503 is ideally suited
for measuring resistive transducers, such as RTDs or thermistors. Each
channel has an amplifier with a selectable gain of 1 or 100 and a lowpass
filter with a 5 Hz cutoff frequency to reject 50/60 Hz noise. The SCXI-1503
can programmatically connect each input to ground, which greatly
improves its accuracy by enabling a self-calibration of each input to
reduce offset drift errors. You can multiplex several SCXI-1503 modules
and other SCXI modules into a single channel on the data acquisition
device, greatly increasing the number of analog input signals that you
can digitize. The SCXI-1306 is a front mounting terminal block that offers
screw-terminal connectivity for the SCXI-1503.
Analog Input
Each of the 16 differential analog input channels feeds to a separate
instrumentation amplifier with a programmable gain of 1 or 100. Each
channel has a fixed 100 μA current excitation. Then the signal passes
through a fixed two-pole, 5 Hz lowpass filter. The CJ sensor input
channel reads the sensor temperature from the terminal block. The
temperature sensor is for cold-junction compensation of thermocouple
measurements. The CJ sensor channel also passes through a 5 Hz
lowpass filter to reject unwanted noise on the SCXI-1503. Along with
the other 16 input channels, the CJ sensor is multiplexed to the output
buffer, where the data acquisition device can read it.
SCXI-1503 current sources continuously provide 16 channels of 100 μA
current excitation. These current sources are on whenever the SCXI
chassis is powered on. SCXI-1503 current sources are designed to be
accurate within ±0.05 percent of the specified value with a temperature
drift of no more than ±5 ppm/°C. The accuracy and stability of these
current sources make them especially well-suited to measuring
resistance to a high degree of accuracy.
Calibration
The SCXI-1503 is shipped with a calibration certificate and is calibrated
at the factory to the specifications described in NI SCXI-1503
Specifications. Calibration constants, stored inside the calibration
EEPROM, provide software correction values that your application
development software uses to correct the measurements for both offset
and gain errors in the module.
Measurement Services Software
NI-DAQmx measurement services software is included with all
National Instruments data acquisition and signal conditioning products.
This easy-to-use software tightly integrates the full functionality of your
NI data acquisition hardware with NI LabVIEW, LabWindows/CVI, and
Measurement Studio for Visual Basic software. High-performance
features include multidevice synchronization, networked measurements,
and DMA data management. Bundled with NI-DAQmx, the Measurement
& Automation Explorer (MAX) utility simplifies the configuration of your
measurement hardware with device test panels, interactive