Strain Gage Module for Compact FieldPoint NI cFP-SG-140 • Accepts full- and half-bridge strain gage inputs directly • Quarter-bridge gages require external bridge-completion resistor • Compatible with load cells, force sensors, and torque sensors • Built-in signal conditioning • 15, 60, and 240 Hz noise rejection • Pulsed excitation to prevent self-heating Module cFP-SG-140 Input Channels 8 • 16-bit resolution • Input ranges software-configurable per channel • 2,300 Vrms bank isolation for transient overvoltage protection • Hot-swappable with autoconfiguration • -40 to 70 °C operating range Resolution 16 bits Input Ranges (Software-Configurable per Channel) ±3.5 mV/V, ±7.5 mV/V, ±30 mV/V, ±60 mV/V 15/60/240 Hz Noise Filter Software selectable All Channel Update Rate1 1.11 to 0.87 Hz (rate varies with filter settings) 1The all-channel update rate refers to the time the module takes to sample all channels. The overall system update rate is affected by other factors, such as the aggregate module update rate and software loop rate. To calculate the system update rate, visit ni.com/info and enter “systemrate.” Overview The National Instruments cFP-SG-140 is a versatile resistance bridge input module for Compact FieldPoint that you can use to measure values from resistor bridges including full- and half-bridge strain gages, quarter-bridge strain gages (using an external completion register), and load and torque sensors. The NI cFP-SG-140 includes built-in excitation, overranging, and onboard diagnostics to ensure trouble-free installation and maintenance. The module measures and linearizes signals on board to return scaled values to your control or monitoring software. The cFP-SG-140 comes with a NIST-traceable calibration certificate, ensuring accurate and reliable analog measurements. Strain Gage With the cFP-SG-140, you can connect directly to industrial sensors or units under test and get high-accuracy measurements. The module filters, calibrates, and scales raw sensor signals to engineering units, as well as performs self-diagnostics to look for problems with the module or wiring. With the cFP-SG-140 module, your software application reads a linearized, calibrated, and scaled value from the I/O module, eliminating the errorprone step of converting binary values. Because the cFP-SG-140 measures in units of millivolts per volt, it can interface with a wide variety of transducers, such as load cells and pressure sensors. The module uses a pulsed excitation of up to 21 mA per channel that turns on and off the excitation to each channel. This reduces self-heating effects and provides more accurate and repeatable strain measurements. The cFP-SG-140 also offers true ratiometric readings to eliminate errors caused by variations in excitation voltage. You can configure each channel on the module for a different excitation level of 2.5, 5, or 10 V. For increased accuracy and noise rejection, the cFP-SG-140 uses a 16-bit delta-sigma ADC with an integrated lowpass filter on each channel, which you can configure for 15, 60, or 240 Hz. With a high-accuracy 16-bit delta-sigma ADC, you also get instrument-quality measurements on an industrially rugged, distributed, embedded system. The cFP-SG-140 has three update rates to fit your application, ranging from 0.87 to 1.11 Hz. These rates vary based on the noise filter setting selected on the module. Overall data throughput depends on software loop speeds and network speeds. With overranging and underranging, the modules can zero out unstrained readings in software to compensate for field devices with span errors of up to 12 percent. Isolation The cFP-SG-140 features optical bank isolation with 2,300 Vrms of breakdown isolation. These Compact FieldPoint modules do not have channel-to-channel isolation. Field I/O Connections Compact FieldPoint modules include a built-in power distribution bus that provides multiple power connections on the module. A field-wired power supply connected to the voltage (V) and common (C) terminals is internally connected to a power distribution bus that offers additional breakout terminals for voltage supply (VSUP) and common (COM). These terminals deliver a convenient way to distribute power to field devices that require external power. Strain Gage Module for Compact FieldPoint 1. 2. 3. 4. Each input channel on the cFP-SG-140 has four terminals: Excitation voltage output (Vexc) Positive signal input (Vin+) Negative signal input (Vin-) Common input (COM) Vexc Vexc Quarter-Bridge Strain Gages External Completion Resistor Vin+ Vin+ Vin– Input Circuitry + – Excitation Voltage Vin– Input Circuitry + – Excitation Voltage COM COM cFP-SG-140 cFP-SG-140 Full-Bridge Strain Gage Half-Bridge Strain Gages Vexc Vin+ Vin– Input Circuitry + – Excitation Voltage COM cFP-SG-140 Wiring Schematic for the cFP-SG-140 Module Ordering Information NI cFP-SG-140 ....................................................................777318-140 Recommended Compact FieldPoint System Products NI cFP-2120 ......................................................................777317-2120 NI cFP-BP-4 ............................................................................778617-04 NI cFP-CB-1............................................................................778618-01 NI PS-5 power supply............................................................778805-90 NI Developer Suite Professional Control Edition ....................777906-03 BUY NOW! For complete product specifications, pricing, and accessory information, call 800 813 3693 (U.S.) or go to ni.com/compactfieldpoint. BUY ONLINE at ni.com or CALL 800 813 3693 (U.S.) 2 Strain Gage Module for Compact FieldPoint Shock and Vibration Specifications Typical for -40 to 70 °C unless otherwise noted. Input Characteristics Number of inputs ................................ Resolution ........................................... Type of ADC ........................................ Filters................................................... Excitation voltage ............................... 8 differential 16 bits, 1 in 65,536 Delta-sigma 15, 60, 240 Hz, user-selectable 2.5, 5, 10 V, user-selectable, current-limited to 21 mA per channel Bridge configurations.......................... Half- and full-bridge circuits, quarter-bridge with external completion resistor Gage factor ......................................... Any (software value) Input impedance ................................. 20 MΩ Offset error 15 to 35 ˚C ...................................... 7.6 µV typ, 28 µV max -40 to 70 ˚C..................................... 50 µV typ, 140 µV max Gain error 15 to 35 ˚C ...................................... 0.06% -40 to 70 ˚C..................................... 0.4% Input noise (60 Hz filter) ±3.5 mV/V ....................................... ±3 LSBpp ±7.5 mV/V ....................................... ±2 LSBpp Other ranges ....................................... ±1 LSBpp All-channel update periods 15 Hz ............................................... 1.15 s 60 Hz ............................................... 0.95 s 240 Hz ............................................. 0.90 s Isolation Voltage NI recommends Compact FieldPoint if your application is subject to shock and vibration. Operating vibration, random (IEC 60068-2-64) ............................. 10 to 500 Hz, 5 grms Operating vibration, sinusoidal (IEC 60068-2-6) ............................... 10 to 500 Hz, 5 g Operating shock (IEC 60068-2-27) ............................. 50 g, 3 ms half sine, 18 shocks at 6 orientations; 30 g, 11 ms half sine, 18 shocks at 6 orientations Safety and Compliance 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 61010-1, CSA 61010-1 Note: For UL and other safety certifications, refer to the product label or visit ni.com/certification, search by model number or product line, and click the appropriate link in the Certification column. Electromagnetic Compatibility This product is designed to meet the requirements of the following standards of EMC for electrical equipment for measurement, control, and laboratory use: • EN 61326 EMC requirements; Minimum Immunity • EN 55011 Emissions; Group 1, Class A • CE, C-Tick, ICES, and FCC Part 15 Emissions; Class A Maximum isolation voltage ................ 250 Vrms, Installation Category II Channel-to-channel isolation.............. No isolation between channels Transient overvoltage.......................... 2,300 Vrms Note: For EMC compliance, operate this device according to product documentation. Physical Characteristics CE Compliance LED indicators POWER (green) ............................... READY (green) ................................ OVERCURRENT (red)....................... Dimensions (including terminal base) .................... Power on and self-test passed Module configured and ready Overcurrent condition on channel 10.9 by 10.7 by 9.1 cm (4.3 by 4.2 by 3.6 in.) Weight................................................. 110 g (3.7 oz) Power Requirement Power from network module .............. 1,000 mW Environmental Operating temperature ....................... Storage temperature........................... Relative humidity ................................ Maximum altitude............................... -40 to 60 °C -55 to 85 °C 10 to 90%, noncondensing 2,000 m; at higher altitudes the isolation voltage ratings must be lowered Pollution degree.................................. 2 This product meets the essential requirements of applicable European Directives, as amended for CE marking, as follows: • 2006/95/EC; Low-Voltage Directive (safety) • 2004/108/EC; Electromagnetic Compatibility Directive (EMC) 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/certification, search by model number or product line, and click the appropriate link in the Certification column. Waste Electrical and Electronic Equipment (WEEE) EU Customers: At the end of their life cycle, all products must be sent to a WEEE recycling center. For more information about WEEE recycling centers and National Instruments WEEE initiatives, visit ni.com/environment/weee.htm. BUY ONLINE at ni.com or CALL 800 813 3693 (U.S.) 3 IN TA PL AN MA IN NI Services and Support P DE LO Y EL OP SERVICE NEEDS V DE NI has the services and support to meet your needs around the globe and through the application life cycle – from planning and development through deployment and ongoing maintenance. We offer services and service levels to meet customer requirements in research, design, validation, and manufacturing. Visit ni.com/services. Training and Certification NI training is the fastest, most certain route to productivity with our products. NI training can shorten your learning curve, save development time, and reduce maintenance costs over the application life cycle. We schedule instructor-led courses in cities worldwide, or we can hold a course at your facility. 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Calibration Services NI recognizes the need to maintain properly calibrated devices for high-accuracy measurements. We provide manual calibration procedures, services to recalibrate your products, and automated calibration software specifically designed for use by metrology laboratories. Visit ni.com/calibration. Repair and Extended Warranty NI provides complete repair services for our products. Express repair and advance replacement services are also available. We offer extended warranties to help you meet project life-cycle requirements. Visit ni.com/services. *351573A-01* 351573A-01 2007-9297-161-101-D ©2008 National Instruments Corporation. All rights reserved. FieldPoint, National Instruments, National Instruments Alliance Partner, NI, ni.com, NI Developer Suite, and SCXI are trademarks of National Instruments. Other product and company names listed are trademarks or trade names of their respective companies. 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