The SCC-ACC01 accelerometer (ACC) input module accepts an active
accelerometer input signal, passes it through a 0.8 Hz highpass filter,
amplifies it, and then passes it through a 19 kHz lowpass Bessel filter and
an output buffer. The module has a fixed gain of 2, so the maximum input
range is ±5 V. The SCC-ACC01 also provides a 4 mA current source for
accelerometer excitation.
Conventions
The following conventions are used in this guide:
<>Angle brackets that contain numbers separated by an ellipsis represent
a range of values associated with a bit or signal name—for example,
P0.<3..0>.
»The » symbol leads you through nested menu items and dialog box options
to a final action. The sequence File»Page Setup»Options directs you to
pull down the File menu, select the Page Setup item, and select Options
from the last dialog box.
This icon denotes a note, which alerts you to important information.
This icon denotes a caution, which advises you of precautions to take to
avoid injury, data loss, or a system crash. When this symbol is marked on
the product, refer to the Read Me First: Safety and Radio-Frequency Interference document, shipped with the product, for precautions to take.
When symbol is marked on a product, it denotes a warning advising you to
take precautions to avoid electrical shock.
When symbol is marked on a product, it denotes a component that may be
hot. Touching this component may result in bodily injury.
Page 2
boldBold text denotes items that you must select in software, such as menu
items and dialog box options. Bold text also denotes parameter names.
italicItalic text denotes variables, emphasis, a cross reference, or an introduction
to a key concept. This font also denotes text that is a placeholder for a word
or value that you must supply.
monospaceText in this font denotes text or characters that you should enter from the
keyboard. This font is also used for the proper names of disk drives, paths,
directories, programs, subprograms, subroutines, device names, functions,
operations, variables, filenames, and extensions.
SC-2345SC-2345 refers to both the SC-2345 connector block and the SC-2345 with
configurable connectors.
SCCSCC refers to any SCC Series signal conditioning module.
SCC-ACC01 Accelerometer Input Module User Guide2ni.com
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What You Need to Get Started
To set up and use the SCC-ACC01, you need the following items:
❑ SC-2345/2350 with one of the following:
–SCC-PWR01
–SCC-PWR02 and the PS01 power supply
–SCC-PWR03—requires a 7 to 42 VDC power supply
(not included)
❑ One or more SCC-ACC01
❑ SCC-ACC01 Accelerometer Input Module User Guide
❑ Read Me First: Safety and Radio-Frequency Interference
❑ SC-2345/2350 User Manual, available at ni.com
❑ SCC Quick Start Guide, available at ni.com
❑ SC-2345 Quick Reference Label
❑ 68-pin E Series DAQ device, documentation, and 68-pin cable
❑ 1/8 in. flathead screwdriver
❑ Numbers 1 and 2 Phillips screwdrivers
❑ Wire insulation strippers
❑ NI-DAQ (current version) for Windows 2000/NT/XP/Me
Note Software scaling of measurements is not supported on the Macintosh operating
Note For general SCC module installation and signal connection information, and
information about the SC-2350 carrier, refer to the SCC Quick Start Guide, available
for download at
Installing the Module
Caution Refer to the Read Me First: Safety and Radio-Frequency Interference document
before removing equipment covers or connecting/disconnecting any signal wires.
ni.com/manuals.
You can plug the SCC-ACC01 into any analog input socket on the
SC-2345. It can function as a single-stage module or as the first stage of
a dual-stage signal conditioning configuration. The socket you choose
determines which E Series DAQ device channels receive the SCC-ACC01
signals, as explained in the Connecting the Input Signals section.
For single-stage input conditioning, plug the SCC-ACC01 into any socket
J(X+1), where X is 0 to 7, and connect the input signals to the module as
described in the Connecting the Input Signals section.
If you use the SCC-ACC01 in a dual-stage configuration, the SCC-ACC01
must be the first-stage module. Plug it into any socket J(X+9) and plug the
second-stage SCC into socket J(X+1), where X is 0 to 7. Connect the input
signals to the SCC-ACC01 as described in the Connecting the Input Signals
section. The SC-2345 connects the output signals of the first-stage SCC to
the inputs of the second-stage SCC. An example of dual-stage conditioning
is an SCC-ACC01 followed by a lowpass filter module (SCC-LPXX).
Although not available for the SCC-ACC01, sockets J9 to J16 are available
for digital input/output conditioning or control with another SCC module.
Refer to the SC-2345/2350 User Manual for more information on
configuring, connecting, and installing SCC modules.
Connecting the Input Signals
Note The signal names have changed. Refer to ni.com/info and enter rdtntg to
confirm the signal names.
Each screw terminal is labeled by pin number <1..4>. Pins 1 and 2 form a
differential (DIFF) analog input channel for measuring the voltage across
the accelerometer. This channel is routed to E Series DAQ device
channel X, where X is 0 to 7 depending on the socket where you plug in
the SCC-ACC01. Pins 3 and 4 carry the 4 mA constant-current excitation
source. Figure 1 shows the SCC-ACC01 signal connections.
SCC-ACC01 Accelerometer Input Module User Guide4ni.com
Page 5
ACC
The signal source can be floating or ground-referenced. The SCC-ACC01
input circuitry includes high-impedance bias resistors typically required for
floating sources. External bias resistors connected to ground are not
required.
For floating signal sources in high-noise environments, connect the
negative terminal of the signal source to the AI GND terminal on the
SC-2345 screw-terminal block to reduce common-mode noise.
For information about how to configure the SCC-ACC01 module using
NI-DAQmx, refer to the SCC Quick Start Guide.
Using the SCC-ACC01
Scaling Voltage Measurements
If you configured the SCC-ACC01 using Measurement & Automation
Explorer (MAX) and are using NI-DAQ, the reading you get from the
E Series DAQ device is properly scaled. Use scaling constants obtained
from your sensor data sheet to convert the accelerometer voltage to the
desired unit, such as newtons, m/s
following steps to scale the readings:
1.Measure the accelerometer voltage.
a.Read the accelerometer channel on the E Series DAQ device
V
ESERIES
b.Calculate the accelerometer voltage using this formula:
Maximum altitude...................................2,000 m
Pollution Degree (indoor use only) ........2
Safety
This product is designed to meet the requirements of the following
standards of safety for electrical equipment for measurement, control,
and laboratory use:
•IEC 61010-1, EN 61010-1
•UL 3111-1, UL 6101B-1
•CAN/CSA C22.2 No. 1010.1
Note For UL and other safety certifications, refer to the product label or visit
ni.com/hardref.nsf, search by model number or product line, and click the
appropriate link in the Certification column.
Electromagnetic Compatibility
Emissions................................................EN 55011 Class A at 10 m
Note Refer to the Declaration of Conformity (DoC) for this product for any additional
regulatory compliance information. To obtain the DoC for this product, visit
ni.com/hardref.nsf, search by model number or product line, and click the
appropriate link in the Certification column.
SCC-ACC01 Accelerometer Input Module User Guide10ni.com
Page 11
SCC-ACC01 Module Pin Assignments
Figure 2 shows the I/O connector pins on the bottom of the module.
4
5
1Pin 12Pin 23PWB Key4 Pin 195Pin 20
Figure 2. SCC Module Bottom View
Table 1 lists the signal corresponding to each pin. AI (X) is an analog input
signal channel of the E Series DAQ device. AI GND is the analog input
ground signal and is the reference for AI (X). A GND is the reference for
the ±15 V supplies and REF 5 V. AI GND and A GND connect to the
SC-2345 at the SCC-PWR connector. GND is the reference for the +5 V
supply.
National Instruments™, NI™, ni.com™, and NI-DAQ™ are trademarks of National Instruments
Corporation. Product and company names mentioned herein are trademarks or trade names of their
respective companies. For patents covering National Instruments products, refer to the appropriate
location: Help»Patents in your software, the patents.txt file on your CD, or ni.com/patents.