SCXI 32-Channel Current Excitation Module
SCXI 32-Channel Current Excitation
NI SCXI-1581
• Use with SCXI-1102 module
for high-channel-count RTD
and thermistor measurements
• 32 channels of 100 µA current
excitation sources
• ±0.05% accuracy per channel
current source
• ±5 ppm/°C maximum
temperature drift
• Screw terminal, BNC connector,
and solder pin connectivity options
• NI-DAQ driver simplifies
configuration and measurement
Operating Systems
• Windows 2000/NT/XP
Recommended Software
• LabVIEW
• LabWindows/CVI
• Measurement Studio
• VI Logger
Driver Software
• NI-DAQ 7
Overview
The National Instruments SCXI-1581 provides 32 channels of 100 µA
current excitation. The high accuracy and stability of these current
sources make them especially well suited for measuring resistance
with a high degree of accuracy. The module is ideal in any application
that requires a 100 µA fixed current excitation, such as RTDs and
thermistors. You can combine the NI SCXI-1581 with the SCXI-1102
to create a high-channel-count RTD measurement system.
Signal Connection
Signals from each channel of the SCXI-1581 connect to screw terminals
located in the SCXI-1300 terminal block. The SCXI-1300 plugs
directly into the front of the module. Alternatively, you can use the
TBX-96, a DIN-rail mountable terminal block that you connect to
the SCXI-1581 with the SH96-96 cable. A general-purpose 96-pin
connector and shell, the SCXI-1310, is available as a low-cost
alternative for custom cabling. Finally, you can select the BNC-2095,
a rack-mounted accessory, for BNC applications.
Data Acquisition and
Signal Conditioning
Description
The 32 current sources on the SCXI-1581 are activated whenever the
SCXI chassis is powered-on. The current sources on the SCXI-1581 are
designed for ±0.05% accuracy of the specified value, with a maximum
±5 ppm/°C temperature drift.
Terminal Block Part Number
Type
Cable Special Functions
SCXI-1300
777687-00 Screw terminals
–
–
Front-mount
BNC-2095
777508-01 BNC connectors
–
Prewired ground
Rack-mount
referencing
777264-01 Screw terminals SH96-96
TBX-96
3 terminals
DIN-rail mount or R96-96
per channel
SCXI-1310
777687-10
Solder pins
–
–
Front-mount
Info Code* Page
scxi1300
328
bnc2095
tbx96
scxi1310
330
331
328
Ordering Information
NI SCXI-1581 ................................................................777966-81
For information on extended warranty and value-added
services, see page 20.
BUY ONLINE!
Visit
ni.com/info
and enter scxi1581.
See page 276 to configure your complete SCXI system.
*For more information about any of these products, please visit
ni.com/info
and enter the info code provided.
Table 1. Terminal Block Options for SCXI-1581
National Instruments • Tel: (800) 433-3488 • Fax: (512) 683-9300 • info@ni.com • ni.com
317
SCXI 32-Channel Isolated Analog Output
and Current Excitation Specifications
SCXI 32-Channel Isolated Analog Output
and Current Excitation Specifications
Specifications
These specifications are typical for 25 °C unless otherwise noted.
SCXI-1581
Excitation
Number of channels.........................................
Current output ..................................................
Accuracy ...........................................................
Temperature drift..............................................
Maximum resistive load...................................
Overvoltage protection.....................................
Power-on state .................................................
32 single-ended outputs
100 µA
±0.05%
±5 ppm/°C
100 k
±40 V
100 µA (nonprogrammble)
SCXI-1124
Analog Output – Output Characteristics
Number of channels.........................................
Resolution.........................................................
Common-mode isolation ..................................
Maximum update rate
1
Single channel ...........................................
All six channels .........................................
6 voltage or current
12 bits, 1 in 4,096
250 V
rms
between channels and channel to earth ground
555 S/s
125 S/s (per channel rate)
Transfer Characteristics
Relative accuracy (INL).....................................
Absolute accuracy
Voltage outputs .........................................
Current output ...........................................
DNL...................................................................
Monotonicity ....................................................
±0.5 LSB maximum
±0.05% FSR maximum
±0.1% FSR maximum
±1 LSB maximum
Guaranteed over temperature
Certification and Compliance
SCXI-1124.........................................................
European Compliance
EMC .................................................................
Table Immunity
Safety.........................................................
North American Compliance
EMC .................................................................
250 V, Cat II working voltage
EN 61326 Group I Class A, 10 m,
EN 61010-1
Voltage Output
Ranges.............................................................. 0-1 V, 0-5 V, 0-10 V, ±1 V, ±5 V,
±10 V, software selectable
Output coupling ................................................ DC
Output impedance ............................................ 0.1 maximum
Current drive .................................................... ±5 mA maximum
Load impedance ............................................... 10,000 pf maximum
Protection ......................................................... Short-circuit to ground
Power-on state ................................................. -10 mV
FCC Part 15 Class A using CISPR
ICSES003 via harmonization to FCC Part 15
Safety ............................................................... UL Listed to UL 3111-1
CAN/CSA C22.2 No. 1010.1
Australian and New Zealand Compliance
EMC ................................................................. AS/NZS 2064.1/2 (CISPR-11)
For a definition of specific terms, please visit
ni.com/glossary
Current Output
Range................................................................
Type, (external power not required) ................
Output impedance ............................................
Current loop supply
Internal.......................................................
External......................................................
Protection .........................................................
Power-on state .................................................
0 to 20 mA
Current sink with internal loop supply,
1 G minimum
15 to 21 V
2
3 to 42 V
2
Short-circuit and open-circuit
0 µA
Data Acquisition and
Signal Conditioning
Dynamic Characteristics
0 to 1 V
270 µs
0.015 V/µs
0 to 5 V
115 µs
0.075 V/µs
Output Range
0 to 10 V
±1 V
100 µs
135 µs
0.15 V/µs
0.03 V/µs
±5 V
65 µs
0.15 V/µs
±10 V
85 µs
0.15 V/µs
Settling time
3
Slew rate
Slew rate (current outputs) .............................. 0.3 mA/µs
Noise
Voltage outputs ......................................... 1 mV°, 0 to 20 MHz
Current outputs.......................................... 10 µA
rms
, 0 to 20 MHz
Stability
Offset temperature coefficient
Unipolar range ........................................... ±1 ppm/°C
Bipolar range ............................................. ±6 ppm/°C
Gain temperature coefficient........................... ±20 ppm/°C
1
Update
rate depends largely on the computer and software. These tests were made using a PCI-6032E
installed in a 500 MHz PIII computer running NI LabVIEW and Windows NT; Not for Waveform Generation.
2
Refer to the SCXI-1124 User Manual for more information.
3
Setting time is to ±0.012% (±0.5 LSB) accuracy for a full scale step.
318
National Instruments • Tel: (800) 433-3488 • Fax: (512) 683-9300 • info@ni.com • ni.com
京公网安备 11010802033920号
EEWORLD
