scxi1121-2.pdf
(
196 KB
)
Pobierz
SCXI Isolated Sensor
Input Modules
SCXI-1121
4 isolated channels
333 kS/s (any gain)
Jumper-selectable gain per channel
Jumper-selectable filter per channel
(4 Hz, 10 kHz)
4 isolated voltage or current
excitation channels
250 V
rms
working isolation
per channel
Signal inputs from ±2.5 mV to ±250 V
Offset nulling and shunt calibration
with the SCXI-1321
SCXI-1122
16 Channels
100 S/s (4 kHz filter), 1 S/s (4 Hz filter)
Software programmable gain per
module
Software programmable filter per
module (4 Hz, 4 kHz)
Two excitation sources (1 voltage,
1 current)
480 V
rms
working isolation
Signal inputs from ±5 mV to ±250 V
Shunt calibration
Driver Software
NI-DAQ
Windows 2000/NT/Me/9x
Mac OS
Application Software
LabVIEW
Measurement Studio
Lookout
Signal Compatibility
compensation, bridge
completion, configurable
voltage and current
excitation, bridge
balancing, and shunt
calibration depending on the configured
terminal block. Each channel is individually
isolated with a working voltage limit of
250 V
rms
between channels or channel to
earth. Finally, the SCXI-1121 is CE certified
as double insulated, Category II, for
250 V
rms
of operational isolation.
SCXI Module
Bridge
RTD
Thermocouple
±2.5 mV
±5 mV
0-20 mA
EXPRESS
CODES
to ±250 V
4-20 mA
SCXI-1121
SCXI-1122
–
For information or to
buy products online,
visit ni.com/catalog
and enter:
Table 1. SCXI Module Compatibility
Overview
National Instruments SCXI-1121 and SCXI-1122 are designed for a
wide variety of sensor and signal inputs requiring isolation. The
SCXI-1121 offers independently configurable isolation amplifiers,
filters, and excitation sources for each channel. The SCXI-1122 offers a
single isolation amplifier, filter, and excitation source for all channels.
Both modules offer 250 V
rms
working isolation and can acquire strain,
RTD, thermocouple, millivolt, volt, 250 V, 0 to 20 mA, and 4 to 20 mA
current input signals. Both modules can multiplex their channels into
a single channel of the DAQ device, and you add modules to increase
channel count. The SCXI-1121 also offers parallel-mode operation.
scxi1121
scxi1122
SCXI-1122
The SCXI-1122 consists of 16 relay multiplexers that route the input
channels to a single isolated instrumentation amplifier and lowpass
filter. You can program all inputs together for a range of ±5 mV to
±250 V. You can program the lowpass filter setting for all input
channels for either 4 Hz or 4 kHz. With this architecture, you are
limited to a maximum sampling rate of 100 S/s for the 4 kHz filter
setting, and 1 S/s for the 4 Hz filter setting. This module also offers
cold-junction compensation, bridge completion, and a single voltage
and current excitation source with remote sensing. You can configure
the SCXI-1122 for 4-wire scanning mode, accepting up to eight 5 k
Ω
devices. You can also connect up to 16 devices in series. Each channel
is individually isolated with a working common-mode voltage of 250
V
rms
between channels or 480 V
rms
channel to earth. Finally, the SCXI-
Analog Input
SCXI-1121
The analog inputs of the SCXI-1121 consist of four isolated
instrumentation amplifiers. You can configure each channel
independently using jumpers for input ranges of ±2.5 mV to ±5 V. The
input range for each channel can be extended to ±250 VDC/±250
VAC with the SCXI-1327 terminal block. Each channel also includes a
lowpass filter that you can configure using jumpers for 4 Hz or 10 kHz.
Each channel offers transducer-specific features such as cold-junction
National Instruments
Tel: (512) 794-0100 • Fax: (512) 683-9300 • info@ni.com • ni.com
507
SCXI Isolated Sensor
Input Modules
Parallel
The SCXI-1121 offers parallel-mode operation. In parallel mode, you
can pass each conditioned channel directly to the analog inputs of the
DAQ device. This configuration requires a dedicated DAQ device and
cable for each module operating in parallel mode.
1122 is CE certified as double insulated, Category II, for 250 V
rms
of
operational isolation.
Modes of Operation
Multiplexer
In multiplexed mode, these modules multiplex all conditioned signals,
along with the optional temperature sensor reading provided on the
MTEMP line, onto channel MCH0 of the rear signal connector, to which
you can connect a single input channel of the DAQ device.
Furthermore, you can connect the multiplexed output of each module
using programmable switches to analog bus 0 of the SCXIbus and to
other modules. Several SCXI modules can operate in this manner with
a single DAQ device. Control circuitry also includes a Module ID
register, which can be read through software for module identification.
Each module also has internal counters for the high-speed
automatic scanning mode with any E Series product. A scan clock
signal from the DAQ device synchronizes the scanning. Using this
hardware scanning mode, you can scan channels at rates up to
333 kS/s (3 µs per channel) for the SCXI-1121, and up to 100 S/s
(10 ms per channel) for the SCXI-1122.
Cold-Junction Compensation
Both the SCXI-1121 and SCXI-1122 can read the cold-junction sensor
from a compatible terminal block that offers a CJC sensor. In
multiplexed mode, both modules must read the CJC sensor as a
separate analog input operation.
Transducer Conditioning
SCXI-1121
The SCXI-1121 offers a configurable, isolated excitation source for
each analog input channel. You can independently configure each
excitation source for 3.33 V, 10 V, 0.15 mA, or 0.45 mA. With this
architecture, you can select from 120
Ω
or 350
Ω
bridge-based
transducers, 100
Ω
RTDs, or up to 10 k
Ω
thermistors on a per-channel
Figure 1. SCXI-1121 Block Diagram
508
National Instruments
Tel: (512) 794-0100 • Fax: (512) 683-9300 • info@ni.com • ni.com
SCXI Isolated Sensor
Input Modules
SCXI Module
Bridge Transducer
RTDs
Thermistors
The isolated current excitation channel is a 1.0 mA
source. This source can drive sixteen 100
Ω
devices, such
as RTDs, connected in series. You can also configure the
SCXI-1122 for 4-wire scanning mode. When configured
for 4-wire scanning mode, the current source can drive
up to eight 5 k
Ω
devices, such as thermistors, and still maintain electrical
isolation between transducers.
120
(3.33 V)
350
(10 V)
350
(3.33 V)
1
⁄
4
1
⁄
2
Full
1
⁄
4
1
⁄
2
Full
1
⁄
4
1
⁄
2
Full
100
< 5 k
< 10 k
SCXI-1121
44444 – 44 4
4
4
4
SCXI-1122
16
16
8
–
–
–
16
16
16
16 (series)
8
–
8 (4-wire)
Table 2. Channel Densities for Various Transducer Configurations
basis. Each channel also includes internal half-bridge completion
circuitry for half-bridge and quarter-bridge measurements.
With the SCXI-1321, you can manually null the offset
of bridges and perform shunt calibration of strain gauges.
The SCXI-1321 includes four software programmable switches that
connect a socketed 301 k
Ω
Calibration
Each channel of the SCXI-1121 has offset potentiometers so you can
calibrate each channel manually.
The SCXI-1122 contains calibration hardware to null-out error
sources. With automatic input zeroing, software programmable
analog switches ground the inputs of the instrumentation amplifier for
offset error calibration. By providing an external reference voltage, you
can perform a two-point calibration to match your system to your
exact operating conditions. An onboard EEPROM stores the
calibration constants for each channel for each input range in a user-
defined area. The EEPROM also stores a set of factory calibration constants
in permanent memory, and cannot be modified. National Instruments
driver software transparently uses the calibration constants to correct for
gain, offset, and excitation source errors.
shunt resistor across the transducer elements.
SCXI-1122
The SCXI-1122 offers one voltage and one current excitation channel
for transducers such as RTDs, thermistors, and bridge-based
transducers. The isolated voltage excitation channel is a 3.333 V
source with internal half-bridge completion and a remote sensing
mode to eliminate lead resistance effects. The SCXI-1122 also includes
software-controlled shunt calibration capabilities for bridge
transducers. When activated, the module switches a 301 k
Ω
shunt
resistor, R
SHUNT
, across one arm of the bridge, from the positive input
to V
EX+
. The shunt resistor is socketed for easy replacement.
0
Figure 2. SCXI-1122 Block Diagram
National Instruments
Tel: (512) 794-0100 • Fax: (512) 683-9300 • info@ni.com • ni.com
509
SCXI Isolated Sensor
Input Modules
Terminal Block
Type
CJ Sensor
Compatible Modules
Cabling
Special Functions
Page
SCXI-1320
Screw Terminals
_
–
539
(777687-20)
Front-mounting
SCXI-1321
Screw Terminals
_
Offset nulling and shunt
539
(777687-21)
Front-mounting
calibration for strain gauges
SCXI-1327
Screw Terminals
_
Extended voltage input range
539
(777687-27)
Front-mounting
SCXI-1121
(to 250 V
rms
)
SCXI-1328
Screw Terminals
_
Isothermal construction
540
(777687-28)
Front-mounting
SCXI-1338
Screw Terminals
_
0 to 20 mA current inputs
540
(777687-38)
Front-mounting
4 to 20 mA current inputs
SCXI-1322
Screw Terminals
SCXI-1122
_
–
539
(777687-22)
Front-mounting
SCXI-1305
BNC Connectors
–
_
BNC connectors
538
(777687-05)
Front-mounting
AC coupling (configurable
per channel)
TBX-1328
Screw Terminals
–
SH32-32A
DIN rail mount
542
(777207-28)
DIN-rail mount
(183230-01)
Isothermal construction
TBX-1329
Screw Terminals
–
SCXI-1121
SH32-32A
DIN rail mount
542
(777207-29)
DIN-rail mount
(183230-01)
AC/DC coupling
Removable screw terminals
SCXI-1330
Solder Pins
–
–
Low-cost connector and
540
(777687-30)
Front-mounting
shell assembly
Table 4. Terminal Block Options for SCXI-1121 and SCXI-1122
Signal Connection
The SCXI-1121 and SCXI-1122 offer a variety of terminal block options.
Front-mounting terminal blocks plug directly into these modules, and
provide screw terminals for signal connections. Alternatively, you can
use DIN-rail mountable TBX-style terminal blocks that connect to the
SCXI module by a cable.
Ordering Information
SCXI-1121
..........................................................776572-21
SCXI-1122
..........................................................776572-22
Accessories
SCXI current resistors (4-pack) ...............................776582-01
See page 470 to configure your complete SCXI system.
Extended Warranty
and Value Added Services
........................................page 880
510
National Instruments
Tel: (512) 794-0100 • Fax: (512) 683-9300 • info@ni.com • ni.com
SCXI Isolated Sensor Input Specifications
Specifications
Maximum for 25 °C unless otherwise noted
Complete Accuracy Table
Absolute Accuracy (15 to 35 °C)
SCXI Module
Nominal
Gain
% of Reading
System Noise (peak, 3 sigma)
Temperatµre Drift
Range
1
Typical
Max
Offset
Single Pt.
Avg
% of
Offset
(jumper
4 Hz
10 kHz
4 Hz
10 kHz
Reading/°C
(°C)
selectable)
SCXI-1121
±250 V
rms
3
0.01
2
0.2548
0.6498
0.5 V
29.8 mV
74.7 mV
5.23 mV
8.3 mV
0.0029
22.0 mV
±250 V
3
0.02
2
0.2548
0.6498
250 mV
14.9 mV
37.4 mV
2.61 mV
4.15 mV
0.0029
11.0 mV
±100 V
3
0.05
2
0.2548
0.6498
100 mV
5.96 mV
15.0 mV
1.05 mV
1.66 mV
0.0029
4.4 mV
±50 V
3
0.1
2
0.2548
0.6498
50 mV
2.98 mV
7.48 mV
523 µV
831 µV
0.0029
2.2 mV
±25 V
3
0.2
2
0.2548
0.6498
25 mV
1.49 mV
3.74 mV
262 µV
415 µV
0.0029
1.12 mV
±10 V
3
0.5
2
0.2548
0.6498
10 mV
596 µV
1.50 mV
105 µV
166 µV
0.0029
460 µV
±5 V
1
0.2478
0.6478
5.0 mV
298 µV
748 µV
52.3 µV
83.1 µV
0.0027
240 µV
±2.5 V
2
0.2478
0.6478
2.5 mV
149 µV
374 µV
26.2 µV
41.5 µV
0.0027
130 µV
±1 V
5
0.2478
0.6478
1.0 mV
59.6 µV
150 µV
10.5 µV
16.6 µV
0.0027
64 µV
±500 mV
10
0.2478
0.6478
508 µV
29.8 µV
74.8 µV
5.23 µV
8.31 µV
0.0027
42 µV
±250 mV
20
0.2478
0.6478
258 µV
14.9 µV
37.4 µV
2.62 µV
4.15 µV
0.0027
31 µV
±100 mV
50
0.2478
0.6478
108 µV
5.96 µV
15.0 µV
1.05 µV
1.66 µV
0.0027
24.4 µV
±50 mV
100
0.2478
0.6478
58 µV
2.98 µV
7.48 µV
0.52 µV
0.831 µV
0.0027
22.2 µV
±25 mV
200
0.2478
0.6478
33 µV
1.49 µV
4.8 µV
0.26 µV
0.55 µV
0.0027
21.1 µV
±20 mV
250
0.2478
0.6478
28 µV
1.19 µV
4.6 µV
0.21 µV
0.51 µV
0.0027
20.7 µV
±10 mV
500
0.2478
0.6478
18 µV
0.596 µV
3.12 µV
0.105 µV
0.247 µV
0.0027
20.4 µV
±5 mV
1000
0.2478
0.6478
13 µV
0.298 µV
2.81 µV
0.052 µV
0.312 µV
0.0027
20.2 µV
±2.5 mV
2000
0.2478
0.6478
11 µV
0.149 µV
2.66 µV
0.026 µV
0.296 µV
0.0027
20.1 µV
Absolute Accuracy (15 to 35 °C)
Temperature Drift
SCXI Module
Nominal
Gain
% of Reading
System Noise (peak, 3 sigma)
Range
1,2
Typical
Max
Offset
Single Pt.
Avg
% of
Offset
(programm-
4 Hz
4 kHz
4 Hz
4 kHz
Reading/°C
(°C)
able)
SCXI-1122
±250 V
rms
0.01
0.1528
0.1528
270 mV
29.8 mV
142 mV
5.9 mV
15.8 mV
0.0032
15.0 mV
±250 V
0.02
0.1528
0.1528
137 mV
14.9 mV
71.2 mV
2.95 mV
7.91 mV
0.0032
7.5 mV
±100 V
0.05
0.1528
0.1528
55.1 mV
5.96 mV
28.5 mV
1.18 mV
3.17 mV
0.0032
3.0 mV
±50 V
0.1
0.1528
0.1528
27.7 mV
2.98 mV
14.2 mV
591 µV
1.58 µV
0.0032
1.5 mV
±25 V
0.2
0.1528
0.1528
14.0 mV
1.49 mV
7.12mV
295 µV
791 µV
0.0032
750 µV
±10 V
0.5
0.1528
0.1528
5.83 mV
596 µV
2.85 mV
118 µV
317 µV
0.0032
300 µV
±5 V
1
0.0578
0.0578
2.75 mV
298 µV
1.43 mV
59.1 µV
158 µV
0.0017
150 µV
±2.5 V
2
0.0578
0.0578
1.48 mV
149 µV
712 µV
29.5 µV
79.1 µV
0.0017
75.2 µV
±1 V
5
0.0578
0.0578
556 µV
59.6 µV
285 µV
11.8 µV
31.7 µV
0.0017
30.2 µV
±500 mV
10
0.0578
0.0578
282 µV
29.8 µV
142 µV
5.96 µV
15.8 µV
0.0017
15.2 µV
±250 mV
20
0.0578
0.0578
145 µV
14.9 µV
127 µV
2.95 µV
14.1 µV
0.0017
7.7 µV
±100 mV
50
0.0578
0.0578
62.8 µV
5.96 µV
112 µV
1.74 µV
12.5 µV
0.0017
3.2 µV
±50 mV
100
0.0578
0.0578
35.4 µV
2.98 µV
56.1 µV
1.31 µV
6.23 µV
0.0017
1.7 µV
±25 mV
200
0.0578
0.0578
21.7 µV
1.49 µV
28 µV
0.89 µV
3.11 µV
0.0017
0.95 µV
±10 mV
500
0.0578
0.0578
13.5 µV
0.596 µV
11.2 µV
0.50 µV
1.25 µV
0.0017
0.50 µV
±5 mV
1000
0.0578
0.0578
10.7 µV
0.298 µV
5.61 µV
0.25 µV
0.62 µV
0.0017
0.35 µV
±2.5 mV
2000
0.0578
0.0578
9.37 µV
0.149 µV
2.8 µV
0.20 µV
0.31 µV
0.0017
0.27 µV
Input Characteristics
Number of channels
Overvoltage protection
Module
Powered On
Powered Off
SCXI-1121
4 differential
SCXI-1121
250 V
rms
250 V
rms
SCXI-1122
16 differential
SCXI-1122
250 V
rms
250 V
rms
Input Signal Ranges.......................................
See Accuracy Table
Inputs protected
Input Coupling
SCXI-1121
CH <0..3>
SCXI-1121
DC (or AC with SCXI-1305)
SCXI-1122
CH <0..15>
SCXI-1122
DC
Transfer Characterisics
Nonlinearity
Maximum working voltage
Module
Signal + Common-mode
Module
% of Full Scale Range
SCXI-1121
Each input should remain within 250 V
rms
of ground
and any other channel
SCXI-1121
± 0.04%
SCXI-1122
± 0.01%
SCXI-1122
Each input should remain within 480 V
rms
of ground
and 250 V
rms
of any other channel
Offset Error ....................................................
See Accuracy Table
Gain Error ......................................................
See Accuracy Table
National Instruments
Tel: (512) 794-0100 • Fax: (512) 683-9300 • info@ni.com • .ni.com
511
Plik z chomika:
Qulakin
Inne pliki z tego folderu:
scc.pdf
(597 KB)
scxi1000.pdf
(194 KB)
scxi1100.pdf
(159 KB)
scxi1102_12.pdf
(184 KB)
scxi1104.pdf
(121 KB)
Inne foldery tego chomika:
Zgłoś jeśli
naruszono regulamin