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 National Instruments 

29

NI WSN-3214 User Guide and Specifications

When powering the NI WSN-3214 from a floating power supply source like an external battery or 
isolated power supply, the measurements are susceptible to picking up noise. National Instruments 
recommends connecting the shield of the cable to both the mounting plate of the strain-gage or the metal 
casing of a bridge-based sensor and the DGND pin on the NI WSN-3214. Or, connect the DGND pin 
on the NI WSN-3214 to Earth GND.

Figure 27.  

Quarter-Bridge Measurements Supplied From a Floating Power Supply

Figure 28.  

Quarter-Bridge Measurements Supplied From an Earth GND Referenced Supply.

Controlling Digital Inputs and Outputs

The following sections discuss how to configure the NI WSN-3214 device for different types of input 
and output, and how to connect external devices to the NI WSN-3214 DIO terminals. 

On the 36-position screw terminal connector, terminals 16–18 and 34–36 are the DIO section. The DIO 
section has the following terminals:

DIO

x

—signal terminal

DGND—ground terminal

DIO PWR—DIO Power positive (required when one of the DIO channels is configured for 

Drive 

High (Sourcing)

 or 

Drive High and Low (Sinking and Sourcing)

 mode) 

EX+

IN+

V

C

R

COMP

/EX–

DGND

NI W

S

N-

3

214

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C

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S

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Mo

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EX+

IN+

V

C

R

COMP

/EX–

DGND

NI W

S

N-

3

214

E

a

rth GND

Reference

Su

pply

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Summary of Contents for WSN-3214

Page 1: ...a four channel low power wireless quarter bridge half bridge and full bridge device that works with other NI WSN 32xx nodes and gateways to form a wireless sensor network Figure 1 shows the NI WSN system components Figure 1 NI WSN System Components 1 NI WSN 32xx Nodes 2 NI 9792 WSN Real Time Gateway 3 NI WSN 9791 Ethernet Gateway 4 NI CompactRIO Chassis 5 NI 9795 WSN C Series Gateway 6 PC Running ...

Page 2: ...e dimensions Figure 2 NI WSN 3214 Device Dimensions Safety Guidelines Operate the NI WSN 3214 device only as described in this user guide Hot Surface This icon denotes that the component may be hot Touching this component may result in bodily injury NI WSN Safety Information The following section contains important safety information that you must follow when installing and using NI WSN products C...

Page 3: ...idelines for Hazardous Locations The NI WSN 3214 is suitable for use in Class I Division 2 Groups A B C D T4 hazardous locations Class I Zone 2 AEx nC IIC T4 and Ex nL IIC T4 hazardous locations and nonhazardous locations only Follow these guidelines if you are installing the NI WSN 3214 in a potentially explosive environment Not following these guidelines may result in serious injury or death Cau...

Page 4: ...onnector tied to earth ground or use the NI recommended external power supply NI part number 780703 01 or equivalent Caution The inputs outputs of this product can be damaged if subjected to Electrostatic Discharge ESD To prevent damage industry standard ESD prevention measures must be employed during installation maintenance and operation This product may become more sensitive to electromagnetic ...

Page 5: ...teries for each node Refer to the Battery Power section for recommended battery types Mounting hardware DIN rail or panel panel mount Ethernet cable connection 1 8 in flathead and number 2 Phillips screwdrivers NI WSN 1 3 1 or later Host PC running Windows 7 Vista XP NI LabVIEW 2011 32 bit or later NI LabVIEW 2011 WSN Module or later optional NI 9792 WSN Real Time Gateway Only NI LabVIEW 32 bit Re...

Page 6: ...ing such as the 36 terminal detachable screw terminal connector Attaching the NI WSN 3282 DIN Rail Optional You can mount the NI WSN 3214 on a standard 35 mm DIN rail using a NI WSN 3282 DIN rail clip NI part number 781074 01 Complete the following steps to mount the NI WSN 3214 on a DIN rail Caution Power off the device before mounting it to the DIN rail Note Use thread forming screws to permanen...

Page 7: ...Installation 2 Insert one edge of the DIN rail into the deeper opening of the DIN rail clip as shown in Figure 5 Figure 5 DIN Rail Clip Installation 3 Press down firmly on the NI WSN 3214 to compress the spring until the clip locks into place on the DIN rail 1 DIN Rail Clip Without Device 2 DIN Rail 2 1 ...

Page 8: ... panel mount accessory to attach the NI WSN 3214 device to a panel or other flat surface The NI WSN 3281 panel mount accessory also includes a magnetic mount for attaching the NI WSN 3214 device to metallic surfaces Figure 6 shows the NI WSN 3214 panel mounting dimensions Figure 6 NI WSN 3214 Device Panel Mount Dimensions 78 74 mm 3 100 in 4 5 mm 5 Ø 177 in 44 02 mm 1 733 in 183 79 mm 7 236 in 55 ...

Page 9: ...accessory using the integrated magnet 2 Slide the NI WSN 3214 device into the panel mount accessory as shown in Figure 7 3 Slide the retention clip down and tighten the panel mount knob to secure the NI WSN 3214 device as shown in Figure 8 4 Optional Secure any I O signal or power supply cabling to the panel mount accessory using a zip tie and the integrated strain relief slots 1 Retention Knob 2 ...

Page 10: ...three number 8 or M4 pan head screws in the mounting panel leaving 0 1 in space under the head of each screw Refer to Figure 2 for the correct hole pattern and dimensions 2 Slide the NI WSN 3214 device onto the panel Note In this configuration the NI WSN 3214 is held in place only by the weight of the device and the friction of the screw attachment Use the DIN rail clip or panel mount accessories ...

Page 11: ...lowing order 1 NI LabVIEW 2011 or later 2 NI LabVIEW Real Time Module 2011 or later required only for NI 9795 and NI 9792 support 3 NI RIO 4 0 or later required for NI 9795 support 4 NI LabVIEW WSN Module 2011 or later 5 NI WSN 1 3 1 or later includes NI MAX Tip NI WSN 1 3 1 or later and NI MAX are available for download at ni com support Note After installation of NI WSN the NI Wireless Sensor Ne...

Page 12: ...ates an explosion risk Do not use rechargeable batteries Refer to the Battery Replacement and Disposal section for information about how to dispose of used batteries Note When using the NI WSN 3214 device on battery power you should configure the device as an end node so that it sleeps most of the time Running a device configured in router mode from battery power greatly reduces the battery life T...

Page 13: ...nect an external power supply to the NI WSN 3214 complete the following steps 1 Remove the 2 position mini combicon plug from the device Loosen the retaining screws if necessary Figure 11 2 Position Mini Combicon Plug 2 Connect the external power supply positive lead to the V terminal 3 Connect the negative common lead to the C terminal 4 Reinstall the 2 position mini combicon plug in the device a...

Page 14: ... NI WSN 3214 device interface Figure 12 NI WSN 3214 Node Interface 1 Antenna 2 WSN Connect Button 3 Signal Strength Status LEDs 4 User LED 5 Battery Slots Polarity Indicators 6 I O Connector 7 Reset Button 8 Pro2 Port Reserved for Future Use 9 5 30 V External Power Input 1 3 4 6 7 9 2 5 8 ...

Page 15: ...Strength LEDS 1 4 blink twice and then display the signal strength for three seconds LED 1 4 OFF Low Signal LED 1 ON LED 2 4 OFF Poor LED 1 2 ON LED 3 4 OFF Fair LED 1 3 ON LED 4 OFF Good LED 1 4 ON Excellent Status Indication Each LED 1 4 blinking in succession Searching for a network LED 1 4 and 2 3 alternate blinking Updating firmware LED 1 4 continuously blinking Error Reboot device If problem...

Page 16: ...om the NI WSN 3214 slight changes in the excitation voltages can cause a mismatch between the internal half bridge completion resistors and the half bridge sensors which results in a change in the measurement offsets National Instruments recommends performing bridge calibrations of quarter bridge or half bridge sensors after connecting all sensors to the NI WSN 3214 and after removing or attaching...

Page 17: ...14 module Sensitivity 0 5 μV V per με for GF 2 0 Figure 14 Quarter Bridge I Circuit Diagram The following symbols apply to the circuit diagram and equations R1 and R2 Half bridge completion resistors located inside the NI WSN 3214 R3 Quarter bridge completion resistor located inside the NI WSN 3214 You can select to use a bridge completion of 350 Ω or 1 kΩ R3 must be equal to the nominal resistanc...

Page 18: ...alibration section Half Bridge Type I This section provides information for the half bridge strain gage configuration type I The half bridge type I measures either axial or bending strain Figure 15 shows how to position strain gage resistors in an axial and bending configurations Figure 16 shows the half bridge type I circuit wiring diagram Figure 15 Half Bridge Type I Measuring Axial and Bending ...

Page 19: ...he specimen you are measuring VCH Measured voltage of the bridge VEX Excitation voltage provided by the NI WSN 3214 Vr Offset compensated ratiometric bridge output defined by the following equation Note The ratio of the bridge output voltage to the excitation voltage is calculated internally on the NI WSN 3214 Shunt Calibration is only supported for quarter bridge If you are switching from using a...

Page 20: ...ding Strain A half bridge type II configuration has the following characteristics Two active strain gage elements One strain gage element is mounted in the direction of bending strain on one side of the strain specimen top while the other is mounted in the direction of bending strain on the opposite side bottom Half bridge completion resistors R1 and R2 are provided by the NI WSN 3214 Sensitive to...

Page 21: ...ration and then perform Offset Null in the software The NI WSN 3214 converts the readings to strain using the following equation Full Bridge Type I This section provides information for the full bridge strain gage configuration type I The full bridge type I only measures bending strain Figure 19 shows how to position strain gage resistors in a bending configuration Figure 20 shows the full bridge ...

Page 22: ...ovided by the NI WSN 3214 Vr Offset compensated ratiometric bridge output defined by the following equation Note The ratio of the bridge output voltage to the excitation voltage is calculated internally on the NI WSN 3214 Shunt Calibration is only supported for quarter bridge If you are switching from using a quarter bridge to a half bridge or full bridge configuration you need to specify 1 for Sh...

Page 23: ...e II configuration has the following characteristics Four active strain gage elements Two are mounted in the direction of bending strain with one on one side of the strain specimen top and the other on the opposite side bottom The other two act together as a Poisson gage and are mounted transverse perpendicular to the principal axis of strain with one on one side of the strain specimen top and the...

Page 24: ...The ratio of the bridge output voltage to the excitation voltage is calculated internally on the NI WSN 3214 Shunt Calibration is only supported for quarter bridge If you are switching from using a quarter bridge to a half bridge or full bridge configuration you need to specify 1 for Shunt Calibration and then perform Offset Null in the software The NI WSN 3214 converts the readings to strain usin...

Page 25: ...Bridge Type III Circuit Diagram The following symbols apply to the circuit diagram and equations R1 Active element measuring compressive Poisson effect νε R2 Active element measuring tensile strain ε R3 Active element measuring compressive Poisson effect νε R4 Active element measuring the tensile strain ε GF Gage Factor specified by the gage manufacturer ν Poisson s ratio defined as the negative r...

Page 26: ...n current is 1 1 mA You cannot use 120 Ω bridges because they require more than 6 4 mA Refer to the Battery Considerations section for more information about how the battery life changes with the type of bridge used Connection Options to Correct for Resistance Errors Wiring resistance can create gain errors in bridge circuits The NI WSN 3214 provides two mechanisms to correct for these errors remo...

Page 27: ... if you are using a 350 Ω full bridge the amount of resistance that can be compensated for is Shunt Calibration Remote sensing corrects for resistances from the EX pins on the NI WSN 3214 to the sensor and shunt calibration corrects for these errors and for errors caused by wire resistance within an arm of the bridge Shunt calibration is most useful with quarter bridge sensors because there may be...

Page 28: ...ffset nulling calibration The NI WSN 3214 measures the bridge while not under load and then uses this measurement as the initial bridge voltage when scaling readings from the bridge This method is simple fast and requires no manual adjustments The disadvantage of the software compensation method in contrast to hardware compensation is that software compensation does not physically remove the offse...

Page 29: ... Measurements Supplied From an Earth GND Referenced Supply Controlling Digital Inputs and Outputs The following sections discuss how to configure the NI WSN 3214 device for different types of input and output and how to connect external devices to the NI WSN 3214 DIO terminals On the 36 position screw terminal connector terminals 16 18 and 34 36 are the DIO section The DIO section has the followin...

Page 30: ...ital Output Operational Modes The channels support the following digital output operational modes Drive High Sourcing Drive Low Sinking 3V TTL Logic Open Collector with Pull Up Drive High and Low Sinking and Sourcing Note When configured in a digital output mode reading the channel returns the state of the pin voltage with TTL thresholds Digital Input Operational Modes The channels support the fol...

Page 31: ... The Drive High Sourcing and Drive High and Low Sinking and Sourcing modes require an external power supply connected to the DIO PWR terminal Drive High Sourcing Drive High Sourcing mode is for devices that require high side drive or a sourcing output When using this mode Connect the device to DIOx and connect the device common to the DGND terminal corresponding to that DIOx terminal The DIOx term...

Page 32: ...alue of 1 and driven low to ground for a DIO output value 0 The DIO line is read with 3V TTL Logic input thresholds A supply voltage is not required on DIO PWR Figure 32 Connecting a Device to the NI WSN 3214 in 3V TTL Logic Mode Drive High and Low Sinking and Sourcing When using Drive High and Low Sinking and Sourcing mode Connect the device to DIOx and connect the device common to the DGND termi...

Page 33: ...not being actively read This can reduce the power consumption of the output device This mode should only be used with output devices that have valid output states within 100 μs of having a low impedance path presented to the output TTL Logic TTL Logic mode is suitable for most 3 V or 5 V logic signals The DIOx terminal has high impedance inputs with TTL Logic compatible thresholds Contact Closure ...

Page 34: ...l If a logical 0 is read instead then the current protection is tripped or a fault is preventing the high side switch from driving the output high Resetting Channels After an Overcurrent Condition To reset the short circuit protection turn off the high side switch by writing a digital value of 0 to the channel Then check the wiring and remove any possible faults The correct functionality of the ci...

Page 35: ...us Waveform Interval and Number of Channels Test Conditions NI WSN 1 Sample per Waveform 50 60 Hz High Rejection 350 Ω Full Bridge Acquisition Radio time slot where waveform data is sent Waveform Sample Period 1 Waveform Sample Rate Waveform Interval Radio Send Data Samples per Waveform Battery Life Years 0 5 1 1 5 2 2 5 3 5 3 4 600 500 400 300 200 100 Waveform Interval Seconds 0 0 3 Channels 4 Ch...

Page 36: ...small number of samples per waveform the largest contributor to the power consumption is the radio communication NI LabVIEW WSN allows you to select the amount of data that you send over the radio and when to send it increasing the expected Test Conditions NI WSN 1 Sample per Waveform 50 60 Hz High Rejection 350 Ω Full Bridge Test Conditions NI WSN 180 Seconds Waveform Interval 50 60 Hz High Rejec...

Page 37: ...mated battery life under common conditions Figure 39 NI LabVIEW WSN Battery Life Versus Time Intervals Number of Channels and Number of Samples per Waveform with No Waveform Sent Over the Radio Test Conditions NI LabVIEW WSN Module up to 10 User defined Variables Sent per Radio Interval 50 60 Hz High Rejection Acquisition Radio time slot where optionally waveform data is not sent Waveform Sample P...

Page 38: ... Module 10 Samples per Waveform 50 60 Hz High Rejection 4 Channels 350 Ω Full Bridge Test Conditions NI LabVIEW WSN Module 10 Samples per Waveform 50 60 Hz High Rejection 4 Channels Battery Life Years 1 0 5 1 5 2 5 2 3 500 400 300 200 100 Time Interval Seconds 0 0 50 Waveforms 10 Waveforms 1 Waveform 600 Battery Life Years 0 5 1 1 5 600 500 400 300 200 100 0 Time Interval Seconds 0 2 4CH 350Ω Half...

Page 39: ...eform Acquisitions Test Conditions NI LabVIEW WSN Module 10 Samples per Waveform 4 Channels 350 Ω Full Bridge 10 Waveforms Acquired 1 Waveform Sent Over Radio for a Sampling Interval Battery Life Years 0 5 1 1 5 2 2 5 3 600 500 400 300 200 100 0 Time Interval Seconds 0 4CH 50Hz Low Power 4CH 50 60Hz High Rejection 4CH 21 5ms Aperture Time 4CH 250us Aperture Time ...

Page 40: ...ectromagnetic interference can adversely affect the measurement accuracy of this product The analog input terminals of this device are not protected for electromagnetic interference As a result this device may experience reduced measurement accuracy or other temporary performance degradation when connected cables are routed in an environment with radiated or conducted radio frequency electromagnet...

Page 41: ...cent of Range Offset Error Full Bridge Half Bridge Quarter Bridge Typical 25 C 5 C 0 1 0 005 1 μV V 0 7 140 μV V 0 5 100 μV V Maximum 40 to 70 C 0 45 0 03 6 μV V 1 200 μV V 1 200 μV V After using shunt calibration for quarter bridge and using remote sensing for full half bridge to remove errors from lead wire resistance Range equals 20 mV V Before offset null The offset error can be removed for cu...

Page 42: ...ions 1 Channel Sampling Rate SPS 2 Channel Sampling Rate SPS 3 Channel Sampling Rate SPS 4 Channel Sampling Rate SPS Total Noise μV Vrms Aperture time 250 μs 4 096 1 560 1 092 862 0 76 Aperture time 400 μs 2 340 992 697 537 0 54 Aperture time 750 μs 1 260 585 404 306 0 38 Aperture time 1 4 ms 668 168 217 164 0 27 Aperture time 2 8 ms 344 86 113 85 0 19 Aperture time 5 5 ms 175 43 57 43 0 14 Apertu...

Page 43: ...channel 24 V Sinking 24 V Sinking with Power Management TTL Logic Contact Closure Input voltage range 3 3 to 24 VDC maximum Filter 60 Hz High Rejection 30 30 30 30 0 08 Filter 50 60 Hz Low Power 27 27 27 27 0 08 Filter 50 Hz 60 Hz High Rejection 13 13 13 13 0 07 Samples per second Table 5 Normal Mode Rejection Filter Characteristics Filter Strength Filter Rejection High rejection 60 dB at 50 and o...

Page 44: ... 4 mA at 30 V 3 2 mA at 15 V Minimum detectable pulse width TTL Logic mode 30 μs 24 V modes 30 μs Contact Closure mode 100 μs Digital Output Modes configurable per channel Drive High Sourcing Drive Low Sinking Drive High and Low Sinking and Sourcing and 3V TTL Logic Open Collector with Pull Up DIO power supply voltage range VDIO_PWR 3 3 to 24 V Sourcing current one channel 0 25 A maximum Sinking c...

Page 45: ...3 5 MHz Channels1 11 24 TX power Americas 17 dBm maximum 50 mW International 10 dBm maximum Modulation type DSSS O QPSK Receiver sensitivity 102 dBm Antenna Connector Female RP SMA connector VSWR 2 0 maximum Impedance 50 Ω Directivity Omni Nominal gain 1 5 dBi Power Requirements The following power requirements specifications are typical at 25 C Battery Power Caution Do not use rechargeable batter...

Page 46: ...60 second sample interval 4 mW at 12 V 5 second sample interval 40 mW at 12 V Router mode3 200 mW at 12 V Physical Characteristics Screw terminal wiring 14 to 24 AWG wire Torque for screw terminals 0 2 to 0 25 N m Dimensions Refer to Figure 2 for device dimensions Weight Approx 242 g 8 5 oz Weight with antenna Approx 256 g 9 oz Calibration You can obtain the calibration certificate and information...

Page 47: ...circuits Such voltage measurements include signal levels special equipment limited energy parts of equipment circuits powered by regulated low voltage sources and electronics Caution Do not connect the system to signals or use for measurements within Measurement Categories II III or IV RF Safety Warning This equipment complies with FCC radiation exposure limits set for uncontrolled equipment and m...

Page 48: ...for intentional radiators EN 300 328 EN 301 489 1 and EN 301 489 17 FCC 47 CFR Part 15C IC RSS 210 Note In the United States per FCC 47 CFR Class A equipment is intended for use in commercial light industrial and heavy industrial locations In Europe Canada Australia and New Zealand per CISPR 11 Class A equipment is intended for use only in heavy industrial locations Note Group 1 equipment per CISP...

Page 49: ...istration to IBPT BIPT is required for private usage outside buildings across public grounds over more than 300m For registration and license please contact IBPT BIPT Voor privé gebruik buiten gebouw over publieke groud over afstand kleiner dan 300m geen registratie bij BIPT IBPT nodig voor gebruik over afstand groter dan 300m is wel registratie bij BIPT IBPT nodig Voor registratie of licentie kun...

Page 50: ... dass sich das Gerät NI WSN 3214 in Übereinstimmung mit den grundlegenden Anforderungen und den übrigen einschlägigen Bestimmungen der Richtlinie 1999 5 EG befindet Eesti Estonian Käesolevaga kinnitabNational Instruments seadme NI WSN 3214 vastavust direktiivi 1999 5 EÜ põhinõuetele ja nimetatud direktiivist tulenevatele teistele asjakohastele sätetele English Hereby National Instruments declares ...

Page 51: ...National Instruments jiddikjara li dan NI WSN 3214 jikkonforma mal htigijiet essenzjali u ma provvedimenti ohrajn relevanti li hemm fid Dirrettiva 1999 5 EC Magyar Hungarian Alulírott National Instruments nyilatkozom hogy a NI WSN 3214 megfelel a vonatkozó alapvetõ követelményeknek és az 1999 5 EC irányelv egyéb elõírásainak Polski Polish Niniejszym National Instruments oświadcza że NI WSN 3214 je...

Page 52: ...s must be sent to a WEEE recycling center For more information about WEEE recycling centers National Instruments WEEE initiatives and compliance with WEEE Directive 2002 96 EC on Waste and Electronic Equipment visit ni com environment weee Battery Replacement and Disposal Battery Directive After replacement recycle the old battery For information about the available collection and recycling scheme...

Page 53: ...er import export data 2012 National Instruments All rights reserved 373304A 01 Sep12 Where to Go for Support The National Instruments Web site is your complete resource for technical support At ni com support you have access to everything from troubleshooting and application development self help resources to email and phone assistance from NI Application Engineers National Instruments corporate h...

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