National Instruments Hardware
National Instruments data acquisition hardware has a modular design; various combinations can be arranged to satisfy a wide range of customized experimental setups. The signal path starts at the sensor. Sensor output is obtained by a module- a computer card designed to read some number of channels from one or more sensor types. Modules are housed in a chassis, which reads data from all modules. Finally, the chassis passes the data to the computer. Signals are sent and acquired through National Instruments LABVIEW software.
Signal conditioning and calibration options can occur at the module or programmatically in the LABVIEW code. All NI DAQ carts have LABVIEW.
For any piece of hardware, specs and manuals are freely available on National Instruments website. The lab can assist in the creation of plugs and connectors for sensor wires; clients are also welcome to consult the relevant module manuals for the pin-out information needed to prepare their own.
Each module listed comes with its corresponding shielded terminal block- a box with screw terminals that makes connecting sensor wires easy.
Although many of the listed modules are generally available, use varies, and additional modules may be required for an experiment. For new hardware, price-sharing/ownership agreements are negotiable; direct inquiries toward one of the lab contacts.
NI PXI Chassis and modules
NI SCXI Chassis and modules
MTS Hardware
The MTS Structural Testing System (STS) data acquisition system has similar capability to NI, but with different components and advantages/limitations. The STS has a wire network that accommodates a variety of sensors (26 strain, 10 LVDT, 3 encoder, and 3 accelerometer channels) and can reach any location in the lab.
Sensor wires
For strain, the sensor wires have a ‘completion box’ that can be fitted with shunt resistors and gage resistors in order to shunt calibrate (in the software) and to accommodate the various bridge completion circuits.
Encoder, LVDT, and accelerometer wires are configured and plugged for lab sensors.
All sensors have adequate length (shielded) to reach anywhere in the strong floor. They are routed in the basement and brought up (through passages in the strong floor) near the test, which helps greatly with organization.
For all sensors, pin schematics are available upon request. The lab can also assist in making plugs.
Controller
The sensor wires link into modules on the MTS controller. These modules can be swapped to customize an experiment; however, it is favorable to swap/expand modules with the NI equipment.
The controller has signal conditioning and calibration options that are operable at the desktop (in the center of operations, known as the control room).
Maximum capacity (combining systems)
Presently, using the fiber-optic module to combine the NI and STS DAQ systems would provide 42 strain gage, 18 LVDT, 3 encoder, 3 accelerometer, and 3 actuators. It is possible to increase the number of certain types of channels with additional NI modules.
Note: strain channels can be exchanged to read DC LVDTs, accelerometers, etc.
Equipment and Instrumentation List
The following equipment is generally (depending on suitability or current use) available for any visiting tester:
LVDTs
All are plugged, configured, ready for use, non-cert. calibrated in lab.
Encoders
Plugged, configured, ready for use
Accelerometers
Plugged, configured, ready for use
Extensometers
Plugged, configured, ready for use, non-cert. calibrated in lab
Load Cells
Plugged, configured, ready for use, non-cert calibrated in lab
Plugs
28 male 6-pin military connectors (enough to connect to all STS strain channels).