CDM-VW300 Series Dynamic Vibrating-Wire Analyzers Revision: 11/13 C o p y r i g h t © 2 0 1 3 C a m p b e l l S c i e n t i f i c , I n c .
Warranty “PRODUCTS MANUFACTURED BY CAMPBELL SCIENTIFIC, INC. are warranted by Campbell Scientific, Inc. (“Campbell”) to be free from defects in materials and workmanship under normal use and service for twelve (12) months from date of shipment unless otherwise specified in the corresponding Campbell pricelist or product manual. Products not manufactured, but that are re-sold by Campbell, are warranted only to the limits extended by the original manufacturer.
Assistance Products may not be returned without prior authorization. The following contact information is for US and international customers residing in countries served by Campbell Scientific, Inc. directly. Affiliate companies handle repairs for customers within their territories. Please visit www.campbellsci.com to determine which Campbell Scientific company serves your country. To obtain a Returned Materials Authorization (RMA), contact CAMPBELL SCIENTIFIC, INC., phone (435) 227-9000.
Table of Contents PDF viewers: These page numbers refer to the printed version of this document. Use the PDF reader bookmarks tab for links to specific sections. 1. Introduction .................................................................1 2. Cautionary Statements...............................................2 3. Initial Inspection .........................................................2 4. Overview ......................................................................3 4.1 4.2 4.3 4.4 4.5 4.
Table of Contents 7.2 7.3 7.4 Using the Datalogger......................................................................... 30 Using the SC-CPI Interface ............................................................... 31 Using Power Supplies........................................................................ 31 7.4.1 CDM-VW300 Series Analyzer Power ....................................... 31 7.4.2 Data-Acquisition System Power................................................. 32 7.
Table of Contents 8.5.1 Diagnostic Codes (Dynamic) ......................................................54 8.5.1.1 Description of Diagnostic Parameters ..............................55 8.5.1.2 Calculating Low- and High-Frequency Boundaries .........56 8.5.1.3 Using Diagnostic Parameters ...........................................57 8.5.1.4 Decoding the Diagnostic Code.........................................57 8.5.1.4.1 Excitation Strength ................................................57 8.5.1.4.
Table of Contents F. Thermistor Information........................................... F-1 F.1 Converting Resistance to Temperature.............................................F-1 F.1.1 Resistance Conversion Example – Geokon Sensor ...................F-1 F.2 Accuracy and Resolution..................................................................F-1 G. CRBasic Program Library ......................................G-1 G.1 Dynamic Measurements ..............................................................
Table of Contents 6-1. 6-2. 6-3. 6-4. 6-5. 6-6. 6-7. 6-8. 6-9. 6-10. 6-11. 6-12. 6-13. 7-1. 7-2. 7-3. 7-4. 7-5. 7-6. 7-7. 7-8. 7-9. 7-10. 7-11. 7-12. 7-13. 7-14. 7-15. 7-16. 7-17. 7-18. A-1. B-1. C-1. C-2. D-1. F-1. F-2. F-3. F-4. Laboratory-mode measurement system..............................................11 12 Vdc power connection on the CDM-VW300................................12 USB receptacle on CDM-VW300 and Type-Micro-B connector of USB cable.......................................................
Table of Contents 7-1. 7-2. 7-3. 7-4. 7-5. 8-1. 8-2. C-1. Summary of CDM-VW300 Configuration Settings .......................... 33 Relationship of Sample Rate and Sensor Frequency ......................... 37 Number of Analyzers and Channels Supported by a Datalogger Writing to CF Card ........................................................................ 45 CDM-VW300 Scan Rate / Datalogger Scan() Interval Pairings ....... 47 CDM-VW300 Channel-Status LED States .......................................
CDM-VW300 Series Dynamic VibratingWire Analyzers Configuring a dynamic vibrating-wire measurement system requires an integrated system-wide approach. Please review this manual before connecting hardware together or to the PC.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers See TABLE 5-1, CDM / Datalogger Compatibility, in Section 5, Specifications, for datalogger compatibility information. Other than a few clearly noted exceptions, any discussion in this manual of the CDM-VW300 also applies to the CDM-VW305. Before using the CDM-VW300, please study • • Section 2, Cautionary Statements Section 3, Initial Inspection Detailed installation, operation, and troubleshooting information can be found in the remaining sections. 2.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 4. Overview Single-coil vibrating-wire sensors are preferred in many applications because they are stabile, accurate, and durable. CDM-VW300 Series Dynamic Vibrating-Wire Analyzers make accurate high-speed measurements of the resonant frequencies of these sensors at sub-second intervals using advanced excitation and signal processing techniques, including spectral analysis.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers FIGURE 4-2. Eight-channel CDM-VW305 wiring panel 4.2 Measurement Rates CDM-VW300 analyzers use patented techniques to measure sensors at rates from 1 to 333.3 Hz. Systems that exclusively require rates slower than 1 Hz should use a Campbell Scientific AVW200-Series Vibrating-Wire Spectrum Analyzer. FIGURE 4-3. Measurement speeds of the AVW200 and CDM-VW300 analyzers 4.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers Vibrating Wire Thermistor Stainless Steel Housing 4-Conductor Cable Two Thermistor Outputs Two Coil Outputs Internal Bulkhead Seal Diaphragm Filter Plucking and Pickup Coils FIGURE 4-4. Single-coil vibrating-wire sensor including coil and thermistor outputs 4.4 Laboratory Mode Laboratory mode allows for examination and validation of specific measurements types without a datalogger, such as might occur before field deployment.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers Vibrating-Wire Sensors CDMVW300 SC-CPI PC CR3000 Datalogger LoggerNet FIGURE 4-6. Field-mode data-acquisition system diagram 4.6 Data Uses Users should consult authoritative sources concerning the use of vibrating-wire data in structural analysis applications. Following is a short introduction to the use of data made available by CDM-VW300 series analyzers. 4.6.1 Static Measurements Each sensor is measured for a static frequency once per second.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 4.6.4 Rainflow Histograms Rainflow histograms are 3-D representations of the rainflow counting algorithm of Matsuiski and Endo (1968). Rainflow histograms can be used to monitor fatigue levels of structures under stress, such as components of a largescale transportation bridge. The histograms are calculated by the CDMVW300 analyzer to ease the processing burden required of the controlling datalogger.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 5.2 Specifications Electrical specifications are valid from –25 to 50 °C unless otherwise specified. Non-condensing environment required. Specifications are subject to change. Compatibility: TABLE 5-1.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers Sensor resonant frequency range: TABLE 5-2. CDM-VW300/305 Sensor Resonant Frequency Range (Hz) Sample Rate Minimum Sensor Frequency Maximum Sensor Frequency 20 290 6000 50 290 6000 580 6000 1150 6000 2300 6000 100 200 3 333.3 3 Effective resolution (precision): TABLE 5-3. CDM-VW300/305 Effective Frequency Measurement Resolution4 Sample Rate (Hz) Noise Level (Hz RMS)5 1 0.005 20 0.008 50 0.015 100 200 0.035 3 0.11 333.33 0.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers Operating temperature Standard: –25° to 50°C Extended: –55° to 85°C Power requirement Voltage: 9.6 to 32 Vdc Typical current drain CDM-VW300: 115 mA @ 12 Vdc CDM-VW305: 190 mA @ 12 Vdc Output CPI: Connects to datalogger. Baud rate selectable from 50 kbps to 1 Mbps. Cable length varies depending on baud rate, number of nodes, cable quality, and noise environment. 2500 ft maximum. USB: Connects to PC. USB 2.0 full speed.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers difficult to resolve. Data-acquisition systems, from the sensors to the telecommunications equipment, are complex. Campbell Scientific equipment and software are among the best available, but the integration process can be demanding and involves trial and error; contingencies should be developed to address possible problems.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 6.1.2 .1.2 Laboratory-Mode Installation Procedure The following procedure sets up the measurement system in laboratory mode: 1. Install DVWTool software on the PC. Do this before connecting the CDMVW300 to the PC. DVWTool installation automatically installs drivers for the CDM-VW300 USB connection. Reference Section 7.1.1, Software and Driver Installation. 2. Connect 12 Vdc power to the CDM-VW300 as shown in FIGURE 6-2. Reference Section 7.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers FIGURE 6-3. USB receptacle on CDM-VW300 and Type-Micro-B connector of USB cable With the driver installed (step 1) and the power connected and live (step 2), connecting the USB cable will start an automatic process that creates a new communication (COM) port for the CDM-VW300 on the PC. Watch the Windows® system tray to see that the PC completes the process. Once complete, a new port will appear as an available communication port in DVWTool. 4.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers NOTE If COM port CDM-VW300 does not appear, there is a problem with the installation of the device driver or the creation of the COM port. See Section 7.1.1, Software and Driver Installation, for remedial steps. Press Connect in the lower left of the DVWTool window. If DVWTool connects with the CDM-VW300, the channel list on the DVWTool interface becomes available and the button at lower left reads Disconnect as shown in the following figure.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 5. Check the operating system version of the CDM-VW300. Reference Section 7.8, Operating System. Operating systems are occasionally updated. To ensure the CDM-VW300 has the latest, search through www.campbellsci.com/downloads for the most recent release. Compare the version information on the website with the version shown in the DVWTool Help | About screen, which is sampled in the following figure. 6. If DVWTool is running, click Disconnect.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers FIGURE 6-4. Sensor connection on a CDM-VW305 Coil Coil Ground VW VW 1 T T CDM-VW300 FIGURE 6-5. Three-wire vibrating-wire sensor connections Coil Coil Ground Thermistor Thermistor VW VW 1 T T CDM-VW300 FIGURE 6-6.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 8. Reconnect 12 Vdc power to the CDM-VW300. 9. Confirm sensor operation. Reference Section 7.12.1, Sensor Validation. Two status LED lights are provided on the CDM-VW300 for each sensor connection. Eight are provided on the CDM-VW305. The following table lists LED functions and interpretations: TABLE 6-1. CDM-VW300 Status LED States Green or red flash at three-second interval Channel is activated. Green flash Response received from sensor.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers are shaded red), consult Section 7.12.2.1, Monitoring with DVWTool Software, for troubleshooting help. 6.2 Field-Mode Installation IMPORTANT — Do not connect the CDM-VW300 analyzer or SC-CPI interface to a PC until AFTER installing DVWTool 1.0 or later or DevConfig 2.04 or later. Consult Section 7.1.1, Software and Driver Installation, for more information. A simple field-mode configuration, using one CDM-VW300, is covered in this section.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers Procedure: 1. Install DVWTool before connecting the SC-CPI or CDM-VW300 to the PC. Reference Section 7.1.1, Software and Driver Installation. 2. Before proceeding, follow the procedure outlined in Section 6.1, Laboratory-Mode Installation for all sensors connected to the CDMVW300. Record settings determined in DVWTool for later use in the CRBasic program.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers Rainflow | Number of Amp Bins RF_AmpBins Rainflow | Low Limit RF_LowLim Rainflow | High Limit RF_HighLim Rainflow | Minimum Change RF_Hyst RF_Form Rainflow | Rainflow Form | reset list A Rainflow | Rainflow Form | total list B Rainflow | Rainflow Form | form list C 1 Scan rate is automatically set based on the datalogger CRBasic Scan() instruction Interval parameter.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers SC-CPI to CDM-VW300 CPI to CPI (RJ-45 to RJ-45) CPI Bus Terminator SC-CPI to Datalogger 12V to 12V G to G C1 to C1 C2 to C2 C3 to C3 FIGURE 6-8. CPI communications links a. Connect the SC-CPI to the datalogger. Reference FIGURE 6-9, Datalogger to SC-CPI Connection. CR3000, CR1000, and CR800 dataloggers require that a SC-CPI interface the datalogger to the CDM-VW300.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers Use the RJ45 CPI cable between the CPI ports of the CDM-VW300 and the SC-CPI interface. Use the yellow tape included in the CPI Network Kit (pn 29370) to differentiate a cable used for CPI bus communications from cables used for Ethernet communications. Connect SC-CPI to CDM-VW300: RJ-45 to RJ-45 FIGURE 6-10. Connecting the CPI ports of the SC-CPI and CDMVW300 c.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 7. As shown in FIGURE 6-12, connect power leads to the CDM-VW300. Do not turn power on until the system is fully assembled. Connect dc power to the Power connector on the side of the CDMVW300. Voltages from 10 to 32 Vdc may be used. Do not connect ac power directly to the CDM-VW300. A convenient power source is the combination of 12V and G terminals on the face of the datalogger. FIGURE 6-12. Power connection 8.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers FIGURE 6-13. Earth ground connections 9. Write or obtain a CRBasic program for the datalogger. Reference Section 7.10, CRBasic Programming, and Appendix G, CRBasic Program Library. CDM-VW300 and CDM-VW305 programs use the following CRBasic instructions: CDM_VW300Config() CDM_VW300Dynamic() CDM_VW300Static() The CRBasic program must be enabled specifically for the CDM-VW300 or the CDM-VW305.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers The following figure points out essential elements of the CRBasic program for a datalogger controlling a CDM-VW300. To simply confirm that readings can be obtained, one of the following example programs can be used. These programs measure only basic frequency: • Appendix G.1.1, 20 Hz Measurement Example – One CDMVW300, Two Channels • Appendix G.1.2, 20 Hz Measurement Example – One CDMVW305, Eight Channels 10.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers A clean display of data, as shown in the previous figure, is obtained by deactivating all but channel 1 in the CRBasic program. If channels 2 through 8 had not been deactivated, erroneous, but perhaps seemingly-real, data would be displayed. Channels 2 through 8 are deactivated by setting line 24 in the CRBasic example in Appendix G.1.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 1. Install either DVWTool 1.0 or later or DevConfig 2.04 or later. 2. Connect the device to the computer with the USB cable. 3. Open the Windows® Device Manager. In Windows® 7, this is done by choosing Control Panel | Hardware and Sound, and then clicking on the Device Manager icon found in the Devices and Printers section. 4. Find the placeholder device (CDM-VW300 or SC-CPI) identified with a super-imposed exclamation point in a yellow bubble box.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers FIGURE 7-1. DVWTool Settings Editor and Data Display NOTE If CDM-VW300 does not appear in the available selections for Com Port, there is a problem with the installation of the device driver or the creation of the COM port. See Section 7.1.1, Software and Driver Installation, for remedial steps. 7.1.2.2 DVWTool Settings Editor See TABLE 7-1, Summary of CDM-VW300 Configuration Settings, for a listing of settings that can be viewed and edited with DVWTool.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers Standard Deviation of Dynamic Frequency (Hz or Hz2) is the standard deviation of the Dynamic Frequency field computed on one-second data. It is output once per second. It is computed after the Output Format, Multiplier, and Offset have been applied. Resonant Amplitude (V) sets the desired amplitude of the steady-state signal response from the sensor.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers FIGURE 7-2. DevConfig Settings Editor Details about using DevConfig can be found in DevConfig Help or in the LoggerNet datalogger support software manual, which is available at www.campbellsci.com. NOTE If a COM port CDM-VW300 does not appear in the available selections for Communications Port, then there is a problem with the installation of the device driver or the creation of the COM port. See Section 7.1.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers Write or obtain a CRBasic program for the datalogger. Reference Section 7.10, CRBasic Programming. Example programs are available in Appendix G, CRBasic Program Library, and at www.campbellsci.com/cdm-vw300-support. 7.3 Using the SC-CPI Interface See Appendix B, SC-CPI Datalogger to CPI Interface. 7.4 Using Power Supplies See Section 7.7.4, CDM-VW300 to Power Connection, for instructions and precautions when connecting power. 7.4.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 7.4.2 Data-Acquisition System Power Power supply requirements will vary depending on system configuration and location.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers If using software to configure the analyzer, which is recommended, physically connect the CDM-VW300 to the PC with a USB cable. See Section 7.7.1, CDM-VW300 to PC Connection, for assistance in making this connection. Check that the software is pointing to the correct communications port. TABLE 7-1, summarizes the configuration settings. Each configuration setting is discussed in the following sections. TABLE 7-1.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers DVWTool PC Software DevConfig PC Software Setting Name Setting Name Setting Description Multiplier Multiplier Multiplier Offset Offset Offset Steinhart-Hart coefficients Steinhart-Hart Thermistor Coeff A Thermistor A Steinhart-Hart Thermistor Coeff B Thermistor B Steinhart-Hart Thermistor Coeff C Thermistor C Rainflow | Number of Mean Bins Rainflow Mean Bins Rainflow | Number of Amp Bins Rainflow Amp Bins Rainflow | Low Limit Rainflow
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 7.5.3 Operating System Version This field reports the version of the CDM-VW300 operating system. This setting is viewable only in DevConfig. 7.5.4 Operating System Date This field reports the release date of the CDM-VW300 operating system. This setting is viewable only in DevConfig. 7.5.5 Analyzer Serial Number This field reports the serial number of the CDM-VW300. The same serial number is on a tag on CDM-VW300 case.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 7.5.11 Channels Enabled Each channel on a CDM-VW300 series analyzer can be individually enabled for measurement. If a channel is not enabled, the LED corresponding to it will not flash. If the channel is enabled, but there is a diagnostic warning, the LED will flash red. If the device is enabled and obtaining a reading properly from the attached sensor, the LED will flash green. Channels are enabled either with check boxes or Boolean values. 7.5.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers Options: • • • 0 = reset histogram each output / 1 = Do not reset histogram. 0 = Divide bins by total count / 1 = use the total of each bin. 0 = Open form (includes half cycles) / 1 = Closed form (use full cycles) Settings in DVWTool are selected from lists. 7.6 Sensor Selection CDM-VW300 series analyzers work well with standard vibrating-wire sensors that use a single-coil circuit design.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 7.7.1 CDM-VW300 to PC Connection A PC to CDM-VW300 USB connection is used in a laboratory-mode installation and in the initial setup and troubleshooting of field-mode installations. Connect a male-USB to type-micro-B male-USB cable between the PC and the CDM-VW300 analyzer; pn 27555, provided in the CDM network kit (pn 29370), which is shipped with each analyzer, can be used. The type-micro-B male-USB connector connects to the CDM-VW300.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers vibrating-wire sensors operate equally well with either polarity position of the two signal wires. Two coil connections (C) are provided on each channel on the CDM-VW300 to which these leads are connected. FIGURE 7-6. Three-wire vibrating-wire sensor connection The third lead is the shield wire, or sensor ground, and should be connected to the ground connection corresponding to the measurement channel.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers FIGURE 7-8. Five-wire vibrating-wire sensor connection Since temperature is a factor that can influence the frequency output of a vibrating-wire sensor, a temperature measurement is often part of the calculation used to convert the frequency output of the sensor to the desired engineering units. A thermistor is a specialized resistor used for measuring temperature and as such has no polarity. 7.7.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers Connect SC-CPI to CDM-VW300: RJ-45 to RJ-45 FIGURE 7-9. SC-CPI and CDM-VW300 CPI ports with RJ45 cable marked with yellow tape Place a terminator in the remaining open CPI port of the CDM-VW300 as shown in FIGURE 7-10. FIGURE 7-10. CPI terminator installed Apply power to the CDM-VW300, the datalogger, and the SC-CPI interface to confirm connectivity. Multiple CDM-VW300 analyzers can be connected to the CPI bus. The following figure shows these connections.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers SC-CPI interface Daisy-chained CPI cables Daisy-chained power leads CPI terminator FIGURE 7-11. Multiple analyzers on a CPI bus 7.7.4 CDM-VW300 to Power Connection Connect 12 Vdc power to the Power In connector on the side of the CDMVW300. Power supplies providing voltages from 9.6 to 32 Vdc, with a minimum 200 mA current rating, may be used. Connect dc power to the CDM-VW300 as illustrated in the following figure.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers Insert small screwdriver to open gates. Leads from pn 13947 transformer FIGURE 7-12. Installing 12 Vdc transformer on the CDM-VW300 In field-mode installations, power is connected and daisy-chained as shown in the following figures. FIGURE 7-13.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 7.7.5 Earth Ground Connections Earth grounding provides protection from static discharge, transients, and power surges. Ground lugs are provided on the CDM-VW300 and the datalogger for connection to earth ground with high-gage wire. Minimum 14 AWG ground wire is recommended. The earth side of the connection should be to a grounding rod or other grounded device. Consult the datalogger manual for more information on earth grounding. FIGURE 7-14.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers FIGURE 7-15. CR3000 and SC-CPI connections NOTE SC-CPI module connects to terminals C1, C2, C3 (not SDM-C1, SDM-C2, SDM-C3). 7.7.7 Maximum Number of Analyzers on a Datalogger The maximum number of active CDM-VW300 or CDM-VW305 analyzers and channels that can be managed by a single datalogger is a function of the dynamic sample or scan rate. The following table lists example configurations that have a full complement of analyzers. TABLE 7-3.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers • These dataloggers get into a state wherein they measure and store so intensely that little time remains to communicate with LoggerNet or RTDAQ software. The CR3000 datalogger is the only datalogger currently available (as of August 2013) that will allow near real-time monitoring of events. 7.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 7.10 CRBasic Programming 7.10.1 Writing Programs In field-mode installations, the system datalogger requires a user-entered CRBasic program. Programs can be written either from scratch using CRBasic instructions or copied from the example programs provided in Appendix G, CRBasic Program Library. The following CRBasic instructions are used. For details concerning each instruction, consult CRBasic Editor Help.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers CDM_VW300Static() captures static readings such as thermistor, static frequency, and standard deviation of dynamic frequencies at 1 Hz. It is used in the main scan inside of a TimeIntoInterval() conditional statement. Set TimeIntoInterval() to capture static data at 1 Hz. Capturing static data less frequently is possible, but when doing so, only the latest static frequency sample will be available.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 7.11 System Adjustments 7.11.1 Frequency Range Assuming a reasonable level of certainty about the maximum and minimum frequency response of a sensor (that is, what frequency values are returned when the sensor experiences maximum and minimum phenomena or stimulus conditions), the minimum and maximum frequency settings (LowFreq and HighFreq in CRBasic CDM_VW300Config() instruction) can be used to implement further noise reduction of the sensor response.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers FIGURE 7-16.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers FIGURE 7-17. RTDAQ screens showing frequencies in Public table If proper frequencies are showing, the datalogger has successfully communicated with the CDM-VW300 and obtained data.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 7.12.2.1 Monitoring with DVWTool Software The Dynamic Vibrating-Wire Tool Box (DVWTool) is a software package that enables a PC to communicate with the CDM-VW300 via USB (no datalogger required), configure CDM-VW300 settings, and display the output of attached sensors. The output data can be graphed on a line graph or in a rainflow histogram. For more information, refer to Section 7.1.2, Using DVWTool. 7.12.2.1.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 8. Troubleshooting CDM-VW300 series analyzers are designed to give years of trouble-free service with reasonable care. However, if factory repair is needed, you must first contact a Campbell Scientific application engineer to obtain an RMA (Return Materials Authorization) number. See the Assistance statement at the beginning of this manual for more information.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers that those readings are correct and can be viewed with RTDAQ or LoggerNet. 4. 8.4 If temperature and battery measurements in step 1 are successful, reconnect the CDM-VW300 to the datalogger and send the 1 Hz program listed in Appendix G.2, Static Measurements, to the datalogger. If the temperature and battery measurement are unsuccessful, contact a Campbell Scientific application engineer.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers one diagnostic code for each measurement. In total, 800 diagnostic codes are received each second. 8.5.1.1 Description of Diagnostic Parameters Excitation strength — reports the voltage applied by the CDM-VW300 analyzer to keep the vibrating-wire of a sensor in motion. Excitation strength is reported as bit values between 0 and 255, which represent excitation voltages between 0 and 6 V.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers and the Maximum Frequency (Hz) entered in DVWTool. The CDM_VW300Config() instruction equivalent to Maximum Frequency (Hz) is the HighFreq parameter. When a high-frequency limit is entered into DVWTool or the CRBasic program, an error window is created that spans the bandwidth between the frequency cut-off requested (Maximum Frequency or HighFreq) and the frequency cut-off the analyzer can actually establish (Actual Max Freq).
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 8.5.1.3 Using Diagnostic Parameters Although a frequency reading may be provided when an amplitude or frequency warning flag is true, the measurement should be accepted only with caution. Rather than risk accepting bad data, consider setting the SysOptions argument of the CDM_VW300Config() instruction to force the analyzer to report the frequency measured under these conditions as NAN.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers LowAmpWarning = (DiagCode AND 256) where LowAmpWarning is assigned a Boolean data type. 8.5.1.4.3 High-Amplitude Warning Flag The tenth bit (29 or 512) corresponds to the high-amplitude warning flag. Use the following expression to isolate the state of this bit: (DiagCode AND 512) Similar techniques to those described in the preceding section for the lowamplitude warning flag can be used with this expression. 8.5.1.4.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 512 – 767 (200 – 2FF Hex) True 1024 – 1279 (400 – 4FF Hex) 1280 – 1535 (500 – 5FF Hex) True True 1536 – 1791 (600 – 6FF Hex) True True 2048 – 2303 (800 – 8FF Hex) 2304 – 2559 (900 – 9FF Hex) True True True 2560 – 2815 (A00 – AFF Hex) True True True The excitation level associated with a diagnostic code can be calculated.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 2. To reset the product to factory defaults, i. From the list at the left of the main DevConfig window, select the product that was just physically connected. A series of tabs related to the selected product is displayed. ii. Select the Communication Port associated with the physical connection. iii. Click Connect. A series of tabs is presented. Select Settings Editor. iv.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers Microsoft and Windows are either registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries. Geokon 4000 and Geokon 4420 are products of Geokon, Inc. CompactFlash is a registered trademark of the SanDisk Corporation.
CDM-VW300 Series Dynamic Vibrating-Wire Analyzers 62
Appendix A. Measurement Theory A.1 Dynamic Vibrating-Wire Measurements The key components of standard, single-coil vibrating-wire sensors are 1) a taut wire suspended between two anchor points, and 2) an electromagnetic coil positioned at the center of the wire. The coil serves two functions: first as an actuator to put energy into the wire and, second, as a pickup to detect the motion of the wire.
Appendix A. Measurement Theory Wire Response Frequency Measurement Excitation Mirrored Oscillator Datalogger Sample Period FIGURE A-1. Timing of dynamic vibrating-wire measurements An important aspect of dynamic measurement timing is synchronizing the process to an external timing source that is independent of the wire oscillation. Synchronization has intrinsic benefits to the measurement quality and also allows simultaneous sampling of multiple channels.
Appendix B. SC-CPI Datalogger to CPI Interface B.1 Introduction The SC-CPI is designed to interface the CR3000, CR1000, and CR800 dataloggers to a network of CDMs (Campbell Distributed Modules) using the CPI bus communications protocol. Only one SC-CPI interface is required per datalogger. The datalogger and the SC-CPI should be installed in the same enclosure. B.2 Quickstart The following figure shows SC-CPI to CR3000, CR1000, or CR800 series datalogger connection wiring.
Appendix B. SC-CPI Datalogger to CPI Interface lug to a suitable ground should be made. Cabling between the datalogger and the SC-CPI should be as short as possible. To configure the SC-CPI with a PC requires a software driver be installed on the PC. This driver is automatically installed when DVWTool or DevConfig software is installed. Once the driver is installed, a USB cable can be connected between the PC and the SC-CPI.
Appendix B. SC-CPI Datalogger to CPI Interface B.4 Specifications Compatibility Dataloggers: Operating temperature: CR800 Series CR1000 CR3000 –25° to 50°C –55° to 85°C optional Power requirement Source: 9.6 to 16 Vdc Load: 50 mA continuous Connectors CPI to CDM: RJ45 Serial to datalogger: Screw terminal Serial to PC: Type-micro-B male USB Certification: Tested in accordance to EM directive 2004/108/EC and BS EN61326:2006 Weight: 0.188 kg (0.415 lb) Dimensions: 15.94 x 7.49 x 3.18 cm (6.
Appendix B.
Appendix C. CDM Devices and CPI Bus Campbell Scientific is introducing the CDM (Campbell Distributed Module) line of peripherals, starting with the CDM-VW300 series of vibrating-wire analyzers. As multiple CDM devices become available, they will be able to be networked to communicate measurement information to a central datalogger. The communications protocol used is the CAN (Controller Area Network) Peripheral Interface (CPI) protocol.
Appendix C. CDM Devices and CPI Bus FIGURE C-1. CPI pin assignments C.1.3 Speed as a Function of Distance TABLE C-1.
Appendix C. CDM Devices and CPI Bus C.1.4 CPI Grounding To keep the common mode of the signals in range, a common reference (ground) connection is advised for any non-isolated communication link. If a ground potential difference exists, then current will flow on the common wire from one end of the cable to the other. This current is restricted only by the dc resistance of the common wire which is often quite low.
Appendix C. CDM Devices and CPI Bus CR3000 Datalogger SC-CPI CPI CDM Device #1 CPI Long Cable Lengths CDM Device #3 CPI FIGURE C-2.
Appendix D. Digits Conversion Vibrating-wire sensors are typically supplied with a calibration report from the manufacturer. Use the calibration data to convert the frequency output of the CDM-VW300 to engineering units. While basic measurement of CDMVW300 analyzers is frequency, which is expressed in hertz (Hz), some calibration reports express the base measurement in terms of 'digits'.
Appendix D. Digits Conversion FIGURE D-1.
Appendix E. Calculating Measurement Error When using a CDM-VW300 analyzer, the basic output of a measurement is frequency (Hz) or frequency squared (Hz2). Vibrating-wire sensors are usually designed with a linear relationship between wire tension and the phenomenon being measured. Further, wire tension usually has a linear relationship to the square of the resonant frequency (f2). Manufacturers typically provide a formula for converting frequency to an engineering unit (UE) in the form, UE = Kf2, Eq.
Appendix E. Calculating Measurement Error where N is the noise value given in TABLE 5-3, CDM-VW300/305 Effective Frequency Measurement Resolution, corresponding to the sample rate being used. E.2 Example Error Calculation: DGSI Embedment Strain Gage For Durham Geo Slope Indicator embedment strain gages, K = G, where G = 4.0624E–03. So, for microstrain, µε = Gf2 And for effective resolution, ∆ µε = 2GfN E.
Appendix E. Calculating Measurement Error or ∆s = GfN / 500 E.
Appendix E.
Appendix F. Thermistor Information F.1 Converting Resistance to Temperature The CDM-VW300 outputs a resistance value for sensors that contain a thermistor. Temperature is normally calculated by applying the resistance to the Steinhart-Hart equation, which converts resistance to temperature. The Steinhart-Hart equation for converting resistance to degree Celsius is as follows: Temperature = 1/(A + B • LN(resistance) + C • (LN(resistance))^3) - 273.
Appendix F. Thermistor Information 3. Steinhart-Hart equation error 4. Precision of the bridge resistors 5. Accuracy of the datalogger voltage measurement 6. Temperature coefficient of the bridge resistors Errors three through six are usually sufficiently small that they can be ignored. The wire resistance is primarily an offset error and its effect can be removed by the initial calibration.
Appendix F. Thermistor Information 0.32 ERROR = (ACTUAL - COMPUTED) DEG C .0.30 0.28 0.26 0.24 0.22 0.20 0.18 0.16 0.14 0.12 0.10 0.08 0.06 0.04 -10 -5 0 5 10 15 20 25 30 COMPUTED TEMPERATURE (C) 1000 FOOT LEAD FIGURE F-2. Temperature measurement error on a 1000 foot lead. Wire is 22 AWG with 16 ohms per 1000 feet. 1.0 ERROR = (ACTUAL - COMPUTED) DEG C 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 -10 -5 0 5 10 15 20 25 30 COMPUTED TEMPERATURE (C) 3000 FOOT LEAD FIGURE F-3.
Appendix F. Thermistor Information 1.6 1.5 ERROR = (ACTUAL - COMPUTED) DEG C 1.4 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 -10 -5 0 5 10 15 20 25 30 COMPUTED TEMPERATURE (C) 5000 FOOT LEAD FIGURE F-4. Temperature measurement error on a 5000 foot Lead. Wire is 22 AWG with 16 ohms per 1000 feet.
Appendix G. CRBasic Program Library The following example programs are compatible with CR3000, CR1000, and CR800 dataloggers without modification. The programs are available for download at www.campbellsci.com/downloads. Look for "CDM-VW300 Example Programs." The programs are named with a .CR3 extension and can be renamed as .CR1 or .CR8 without modification to run on the CR1000 or CR800 dataloggers. To use programs from this library, 1. Select the desired program and save it to your PC. 2.
Appendix G. CRBasic Program Library 'Offset (shift) to be applied to sensor output frequency Dim Off(2) = { 0.0, 0.0} 'Steinhart-Hart coefficients [A,B,C] for converting thermistor ohms to 'temperature in Celsius. Specifying zeroes for A,B,C results in a reading in Ohms. Dim SteinA(2) = { 0.0, 0.0} Dim SteinB(2) = { 0.0, 0.0} Dim SteinC(2) = { 0.0, 0.
Appendix G. CRBasic Program Library 'Standard Deviation of the dynamic readings that occurred during the latest one-second interval Public DynStdDev(8) 'The following arrays are used to configure the CDM-VW300 series device. Refer to the 'CDM_VW300Config instruction used below.
Appendix G. CRBasic Program Library G.1.3 20 Hz Measurement Example — Three CDM-VW305s, 24 Channels '===20Hz-3Devices8Ch_3-25-13.CR3=== 'CR3000 datalogger 'CDM-VW305 vibrating-wire analyzer 'Program to read 20-Hz dynamic data from three CDM-VW305 analyzers (8x3=24 channels) 'IMPORTANT -- Ensure that the CPI addresses coded on the following lines matches the addresses 'reported for each attached analyzer in the DevConfig or DVWTool software.
Appendix G.
Appendix G.
Appendix G. CRBasic Program Library 'Shared rainflow configuration (not used, but required as configuration arguments) Dim RFMB(8) As Long = { 20, 20, 20, 20, 20, 20, 20, 20} Dim RFAB(8) As Long = { 20, 20, 20, 20, 20, 20, 20, 20} Dim RFLL(8) = { 400.0, 400.0, 400.0, 400.0, 400.0, 400.0, 400.0, 400.0} Dim RFHL(8) = {4000.0,4000.0,4000.0,4000.0,4000.0,4000.0,4000.0,4000.0} Dim RFHY(8) = { 0.005, 0.005, 0.005, 0.005, 0.005, 0.005, 0.005, 0.
Appendix G.
Appendix G. CRBasic Program Library Dim RFHY(2) = Dim RFOF(2) As Long = { 0.005, 0.
Appendix G. CRBasic Program Library 'via excitation, given in volts. This should be in the range 0.010 to 0.001 Dim Max_AMP(8) = { 0.002, 0.002, 0.002, 0.002, 0.002, 0.002, 0.002, 0.
Appendix G. CRBasic Program Library G.1.7 50 Hz Measurement Example — Three CDM-VW305s, 24 Channels '===50Hz-3Devices8Ch_4-25-13.CR3=== 'CR3000 datalogger 'CDM-VW305 vibrating-wire analyzer 'Program to read 50-Hz dynamic data from three CDM-VW305 analyzers (8x3=24 channels) 'IMPORTANT -- Ensure that the CPI addresses coded on the following lines matches the addresses 'reported for each attached analyzer in the DevConfig or DVWTool software.
Appendix G.
Appendix G. CRBasic Program Library Dim Enable(2) As Long = { 1, 1} Dim Max_AMP(2) = { 0.002, 0.002} Dim F_Low(2) = { 300, 300} Dim F_High(2) = { 6000, 6000} Dim OutForm(2) As Long = { 0, 0} Dim Mult(2) = { 1.0, 1.0} Dim Off(2) = { 0.0, 0.0} Dim SteinA(2) = { 0.0, 0.0} Dim SteinB(2) = { 0.0, 0.0} Dim SteinC(2) = { 0.0, 0.0} 'Rainflow-Histogram configuration Dim RF_mean_bins(2) As Long = { MBINS, MBINS} 'Mean Bins Dim RF_amp_bins(2) As Long = { ABINS, ABINS} 'Amplitude Bins Dim RF_Lo_lim(2) = { 400.0, 400.
Appendix G. CRBasic Program Library G.1.9 50 Hz Measurement Example — One CDM-VW305, Eight Channels, Rainflow Histogram '===RFH-50HzExample8Ch_4-25-13.CR3=== 'CR3000 datalogger 'CDM-VW305 vibrating-wire analyzer 'Program to read 50-Hz dynamic data from one CDM-VW305 analyzer measuring eight channels. 'Demonstrate use of rainflow histogram. 'IMPORTANT -- Ensure that the CPI address coded on the following line matches the address 'reported for the attached analyzer in the DevConfig or DVWTool software.
Appendix G.
Appendix G. CRBasic Program Library Public Temp(2) : Units Temp() = DegC ' Temperature in DegC Public TempBL(2) : Units TempBL() = DegC ' Temperature Baseline in DegC Public StrainStdDev(2) : Units StrainStdDev() = Microstrain 'StdDev of dynamic strain readings Public ZeroMode 'Mode variable for baseline/offset zeroing calibration 'Diagnostic Code flags Public ExciteStr(2) : Units ExciteStr() = Volts 'Excitation strength on the VW channel in volts Const VoltFactor = 1/42.
Appendix G.
Appendix G. CRBasic Program Library Public DCode(2) As Long 'Dynamic diagnostic code Public StaticStrain(2) : Units StaticStrain() = Microstrain 'Static (1Hz) strain reading in 'microstrain Public StaticDigits(2) 'Calculated Static (1Hz) Digits output (for troubleshooting).
Appendix G.
Appendix G. CRBasic Program Library Dim OutForm(2) As Long = { 1, 1} 'Use a multiplier of 0.001 to divide by 1000 and get digits 'Then scale further to get to Strain Dim Mult(2) = { 0.001*GageFactor*NomBatchFactor, 0.001*GageFactor*NomBatchFactor} 'Digits (Hz^2/1000) times G times B results in strain Dim Off(2) = { 0.0, 0.0} 'Use Steinhart-Hart coefficients To get Thermistor output in DegC Dim SteinA(2) = {1.4051E-3, 1.4051E-3} Dim SteinB(2) = { 2.369E-4, 2.369E-4} Dim SteinC(2) = { 1.019E-7, 1.
Appendix G. CRBasic Program Library G.1.13 50 Hz Measurement Example — One CDM-VW300, Two Geokon 4000 Sensors with FieldCal() and TableFile() to CF '===Geokon4000-50Hz2ChEventTableFile_4-25-13.CR3=== 'CR3000 datalogger 'CDM-VW300 vibrating-wire analyzer 'Program to read 50-Hz dynamic data from one CDM-VW300 measuring two Geokon 4000 strain gages. 'Write data to CF card at each event. 'Demonstrate use of TableFile() with Option 64, DataEvent(), and DataInterval() to conserve ' data storage.
Appendix G. CRBasic Program Library DataInterval (0,1,Min,10) 'Using TableFile, write the 1 minute averages out each '15 minutes to a file on the CRD (Compact Flash) device TableFile ("CRD:"&Status.StationName(1,1)&".
Appendix G. CRBasic Program Library G.1.14 100 Hz Measurement Example — One CDM-VW300, Two Channels '===100Hz-1Device2Ch_3-25-13.CR3=== 'CR3000 datalogger 'CDM-VW300 vibrating-wire analyzer 'Program to read 100-Hz dynamic data from one CDM-VW300 analyzer measuring two channels 'IMPORTANT -- Ensure that the CPI address coded on the following line matches the address 'reported for the attached analyzer in the DevConfig or DVWTool software.
Appendix G. CRBasic Program Library Sample (2,Diag(),IEEE4) EndTable BeginProg '100 Hz/10msec scan rate Scan(10,msec,500,0) CDM_VW300Dynamic(CPI_ADDR,Freq(),Diag()) 'Get dynamic readings CallTable dynamic If TimeIntoInterval (0,1,Sec) Then 'Process static data only once per second CDM_VW300Static(CPI_ADDR,StaticFreq(),Therm(),DynStdDev()) 'Get static readings CallTable static EndIf NextScan EndProg G.1.15 100 Hz Measurement Example — One CDM-VW305, Eight Channels '===100Hz-1Device8Ch_4-25-13.
Appendix G. CRBasic Program Library Dim RFHL(8) = Dim RFHY(8) = Dim RFOF(8) As Long = {4000.0,4000.0,4000.0,4000.0,4000.0,4000.0,4000.0,4000.0} { 0.005, 0.005, 0.005, 0.005, 0.005, 0.005, 0.005, 0.005} { 100, 100, 100, 100, 100, 100, 100, 100} 'Configure the CDM-VW300 series device. Use the variable arrays declared above.
Appendix G. CRBasic Program Library Dim Dim Dim Dim Dim Dim Dim Dim Dim SteinA(2) = SteinB(2) = SteinC(2) = RFMB(2) As Long = RFAB(2) As Long = RFLL(2) = RFHL(2) = RFHY(2) = RFOF(2) As Long = { 0.0, 0.0} { 0.0, 0.0} { 0.0, 0.0} { 20, 20} { 20, 20} { 400.0, 400.0} {4000.0,4000.0} { 0.005, 0.
Appendix G.
Appendix G.
Campbell Scientific Companies Campbell Scientific, Inc. (CSI) 815 West 1800 North Logan, Utah 84321 UNITED STATES www.campbellsci.com • info@campbellsci.com Campbell Scientific Africa Pty. Ltd. (CSAf) PO Box 2450 Somerset West 7129 SOUTH AFRICA www.csafrica.co.za • cleroux@csafrica.co.za Campbell Scientific Australia Pty. Ltd. (CSA) PO Box 8108 Garbutt Post Shop QLD 4814 AUSTRALIA www.campbellsci.com.au • info@campbellsci.com.au Campbell Scientific do Brasil Ltda. (CSB) Rua Apinagés, nbr.
