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instruNet provides tens of microvolts
of absolute accuracy instead of tens
of millivolts, at the same cost and at the
same throughput rates as typical general
purpose data acquisition boards. It does
this with a completely different topology
where the analog electronics are close
to the sensor in electrically quiet boxes
outside your PC, and noisy digital
electronics are left inside the computer.
The external boxes contain signal
conditioning amplifiers for each channel
and can directly attach to sensors such
as thermocouples, thermistors, RTDs,
strain gages, resistance sources, current
sources and voltage sources. The box
returns engineering units to your PC
(e.g. °C, Volts, Amps).
At the heart of the real-time system
is a PCI or PC-card controller board
that plugs into a Windows 95/NTx86
or Macintosh computer. Each controller
contains a 32 bit microprocessor
with 256KB of RAM that manages the
external "network" of devices. All
real-time tasks are off-loaded to this
processor, therefore the host computer
is not burdened with real-time issues.
Each instruNet iNET-100 box provides,
16 single-ended/8 differential analog
inputs, 8 analog outputs and 8 digital
I/O lines. The iNET-100 includes
44 screw terminals. The iNET-100B
version adds 16 BNCs for analog inputs.
The controllers themselves provide
10 counter/timer channels each of
which can function as a digital input
bit, a digital output bit, a clock output
channel or a period measurement
input channel.
Distributed and Expandable
The instruNet system is ideally suited
for distributed measurement and control
systems. The network cable can extend
up to 1000 feet. Each controller card in
the PC can connect to up to 16 instruNet
boxes for a total number of 256 analog
inputs, 128 analog outputs and 128 digital
I/O. For additional inputs, multiple
controller cards can be placed in one
computer with the maximum number of
controller cards limited only by the number
of available slots in the computer.
Since each controller card has its own
microprocessor, multiple cards do not
place any additional burden on the
computer. It should be noted that multiple
instruNet boxes on a single network may
degrade the maximum system throughput
of 166Ks/sec.
High Current Version (HC)
The INET-100HC is similar to the INET-
100, yet the voltage output channels
have a higher drive capability, providing
up to 15mA of current to capacitive
loads as high as 0.01uF. The INET-100
and INET-100B devices support only
4mA/.001uF voltage output drive. The
INET-100HC is recommended for use
with sensors that require excitation,
such as strain gages, RTDs and
thermistors since these sensors may
exceed the current or capacitive drive
limits of the INET-100 or INET-100B.
The INET-100HC provides greater
compatibility with sensors that have
capacitive loading on the excitation
lines, therefore, the HC version is
recommended for all sensors requiring
excitation including RTDs and
thermistors. Since the HC version has a
greater power demand, an external
power supply must be used. The INET-312-8 can be used to
power up to three INET-100HC boxes.
Software
instruNet World, is a FREE application
program. It manages, monitors and
operates the instruNet system. It digitizes
long continuous waveforms, spools them
to disk, views incoming waveforms in
real-time and then allows post acquisition
viewing-much like an oscilloscope or
strip chart recorder.
instruNet World provides a spreadsheetlike
environment where one can set and
view channel parameters such as sensor
type, integration time, analog filter, and
digital filter. Each channel has its own
row in the spreadsheet, with the various
options in the columns.
instruNet is also compatible with a variety
of off-the-shelf software products including
TEST Point, SuperScope II
Macintosh; Microsoft Excel 8 for Windows,
DasyLab and Labtech Notebook (consult
the factory for the availability of
DasyLab drivers).
For users writing their own programs,
instruNet includes drivers callable from
any 32 bit C compiler, and Visual Basic
(v4.0 or greater). The driver includes a
main routine, called "iNet( )", that reads
or writes any of the options or channels
on the system. Optional drivers are also
available for LabVIEW software.
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InstruNet World Plus Software(for Windows 95/98/NT/2000/XP)
InstruNet World Plus Software is an option that adds
valuable features to the standard
instruNet World software which is
included with instruNet hardware. It
enables one to digitize, plot, control,
analyze, and save to disk A/D, D/A, and
digital I/O data from InstruNet hardware.
Additionally, it enables one to define their
own instrument front panel with buttons,
popup menus, edit fields, dynamic text,
text editor regions, and waveform graphs.
InstruNet World Plus is programmed with
a simple script language that can define
tasks such as control loops. For example,
one can type "Dac1 = OnOff (Ain1, 3)" to
define D/A #1 as a function of A/D #1.
Specifications
Analog Inputs Number: 16 single-ended/8 differential
Resolution: 14-bit
System Throughput: 166K samples/sec
A/D Conversion Time: 4 µs min
Signal To Noise Ratio: 78 dB
Linearity: Differential ±1.5 LSB; Integral ±2 LSB
Input Overvoltage Protection: ±15 V
Input Impedance: >22 MΩ, 3pf
Common Mode Voltage: ±5 V min (CMR ±80 dB)
Gain and Offset Drift: ±5 ppm/°C of 5 V FSR; offset self calibrated to 0 Thermistor Accuracy/Ranges
All OMEGA® 44xxx series thermistors supported. (Contact factory for other thermistors.) One user supplied shunt
resistor per thermistor channel is required.
| Range | Shunt | Accuracy |
| -80 to 40°C | 47KΩ | ±0.2°C |
| 0 to 70°C | 4.7KΩ | ±0.1°C |
| 0 to 200°C | 200Ω | ±0.4°C |
Analog Outputs Number: 8
Resolution: 8 bit
Output Range: ±5 V @ 5 mA for iNET-100/100B, ±5 V @15 mA for iNET-100HC
Output Protection: Short-to-ground continuous
Output Settling Time: 4µs (to ±1/2 LSB, ±5 V step)
Analog Output Accuracy: ±0.4%
Digital Coupling: ±20 mV
Gain and Offset Drift: ±10 ppm/°C of 5 V FSR; and ±5 µV/°C offset drift
Digital I/O Number: 8 non-latching inputs and 8 latching outputs at 8 bi-directional screw terminals
Input Levels:
VIH = 3.2 V min to 12 V max;
VIL = 1.0 V max to -12 V min
IIH = -200 µA, Vi = 3.2 V;
IIL = -0.5 mA max.
Output Levels:
VOH = 2 V min to 5 V max;
IOH = -0.5 mA max.
IOL = 500 mA max, VO=1.7 V;
IOL = 50 mA max, VO = 0.7 V
For additional information
on InstruNet World Plus software see the "Related Links" section below.
For user manuals and application notes visit the instrunet web site.
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† All dollar amounts on this site are shown in US currency.
Note: The iNET-2xx controllers include a complete users manual, instruNet World data acquisition software, driver software and network terminator. The iNET-100/100B includes a 10 ft. connecting cable.
Ordering Example: (1) iNET-100B instruNet external A/D box with screw terminal and BNC connections, (1) INET-200 PCI controller card = $1280
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Related Links -
Related Products
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Related Products
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iNET-iWPLUS:
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Data Acquisition and Control Software for use with instruNet Data Acquisition Systems
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SWD-DASYLAB:
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DASYLab Data Acquisition System
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Keywords:Data acquistion thermocouple RTD strain bridge PCI Card sensor data logger
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