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johng

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Everything posted by johng

  1. There is a good overview of GSM techonology at the GSM World website and also at wikipedia... http://www.gsmworld.com/technology/gsm/index.htm http://en.wikipedia.org/wiki/GSM Most GSM carriers no longer allow circuit switched connections. When setting up your account (sometimes called provisioning a SIM), you will want to make sure GPRS is enabled. You do not need voice or SMS service (although SMS won't hurt if it is bundled with the GPRS service) in order to get your GSM iPack transmitting data!
  2. We've seen some confusion with the procedure for loading the APN into a GSM iPack being configured for GPRS service. The thing to remember is that you must send the APN into the iPack as a "seperate transaction" using the "send" button on the "set up phone window" in SDR's "Modify iPack Setttings" screen. Unfortunately, due to technical limitations, the APN will NOT be transferred to the iPack when you use the "save to iPack" selection in the "Modify iPack Settings" screen. So, to summarize, the user would have to "save to iPack" to save the ISP information into the iPack and then go to "set up phone" window, type in the APN and press "Send". This is a 2-step process. If you receive an IE 075 while trying to use GPRS, it is a good idea to press "get" to make sure the APN is properly loaded.
  3. A potentiometer wind vane such as the NRG 200P has 3 connection points. One at either end of the potentiometer and one at the potentiometer wiper. The potentiometer wiper moves with the vane tail relative to the fixed base, which produces the ratiomentric signal output of the vane. Using the 3 connections, there is one correct way to wire the vane and 5 incorrect ways. Of the 5 incorrect ways to wire the vane there is only one way in which you can "correct" the data (excitation and ground are swapped while signal is correct). There is another post for this case in our Technical Knowledgebase. We developed a rough guide as to how the various wiring scenarios look on the logger screen. The guide may also be helpful in determining if one of two vanes is miswired by comparing the data from each. Be sure to check your connections at the site! VaneWiring.pdf
  4. Hi - Unfortunately, we do not have any further recomendations at this time. By looking at field data alone, there is not a method to detect the vibratory mode in sensors that are not paired. Depending on your level of concern, you may want to consider post-calibration testing of "single" sensors from these masts. The calibration test result will inform you about the sensor performance. Thanks
  5. Hi - It appears that the sensors you have are older than the potentially affected group. OTC17174 was produced in 2004. The sensor without a serial number on it may have a date code label at the sensor base which specifies the sensor age. If the sensor does not have this label, it is also older than the potentially affected group. The sensors 2820, 2803 and 2798 are also likely to be older NRG sensors which are not potentially affected but it would be good to check for the label at the sensor base. 6567-16 is not an NRG serial number format. Check for the datecode label.
  6. For additional corrosion protection of your logger and sensor wiring, applying a petroleum jelly (Vaseline, non-corrosive) to all of the sensor and logger terminals can be effective. Other options include commonly available dielectric grease which is purpose made for preventing corrosion of electrical connections. The grease is non-conductive (so there is no need to worry about electrical leakage or shorts), is very slippery and available at auto parts stores. One such example is: http://www.jamestowndistributors.com/userportal/show_product.do?pid=8196
  7. Hi - I do see that the 7 m/s bin appears not to contain as much data as the other bins. However, it is difficult to imagine what is actually occurring from this graphic. If you wish to send NRG some RWD data, we would be happy to take a look at it for you. Please send it along with a brief description of the issue to support@nrgsystems.com. Thanks!
  8. Hi Juli?n, Can you send the specification sheet of the proposed wind vane to us at support@nrgsystems.com ? We need to know the output signal definition before we can make a recomendation. Thanks!
  9. Unfortunately, there is not a way to turn off the headers in the TXT files.
  10. Hello Claudio, That sounds like an interesting project. The Hybrid internal electronics are very fast. Both the hybrid anemometer and vane provide a continuous (square wave) output signal with frequency proportional to either wind speed or wind direction. As for the performance characteristics, we do not have official published specifications for the items you asked for. However, I've talked with our engineering department in order to get you some unofficial numbers to plug into your model. Unofficially, the answers are: Distance Constant = 1.5m (by experimental test) Rotational Inertia = 270000 g*mm^2 (Per SolidWorks Model) Rotational Damping = 0.2*critical (aerodynamic damping only (very low friction), experimental estimate) I hope this helps you with your model! If you have any other questions, please don't hesitiate to contact us directly at support@nrgsystems.com. Thanks!
  11. Hi - Unfortunately, there is no way to bypass SDR to convert RWD files to TXT. However, SDR is callable via a scriptable command line interface (under Windows) using command line switches. Please see the application note "Automation of Symphonie Data Retriever" for more details. Thanks!
  12. Hello David - Yes you are correct. Every NRG datalogger has a "model number" that is read by our software from the raw data files. The "Bad or unsupported model" error pops up when the software cannot understand the model number information. As you said, In order to process data from a SymphoniePLUS logger, you will need to download the latest revision of Symphonie Data Retriever software (version 6 or higher) as it understands the newer SymphoniePLUS model number. If you do not have SDR 6.0 (or higher) and you try to process a SymphoniePLUS RWD file, you will receive a logger model number error. As a side note, SDR 6.0 is backward compatible with Symphonie, 9300, 9200-PLUS and Wind Explorer data, and the user interface remains largely unchanged. Thanks!
  13. Hi Colin, I believe this is the link you are looking for...let us know if you have any other questions. http://www.nrgsystems.com/sitecore/content/StandAlonePages/40C_Progress_Report.aspx Thanks!
  14. Hi - The outer numbers are the Turbulence Intensity (TI) for each sector. Higher values represent more turbulent winds while lower values represent less turbulent winds. I've included a definition of TI from our knowledgebase... Calculation of Turbulence Intensity on SDR wind rose report Turbulence intensity (Ti)is defined as the windspeed interval standard deviation (SD) divided by the windspeed interval average (AVG)... Ti = SD/AVG On the windrose, the samples are first sorted by direction into sectors. In each sector, there will be "n" samples. A Ti is calculated for each sample and an average Ti is then created for the sector... WindRose Ti for each sector = (SD/AVG + SD/AVG + SD/AVG...n)/n Note that SDR defaults to 16 sectors for a standard windrose. Thanks!
  15. Hello Edward - I'm not sure you ever received an answer... To create TXT files AND import into the database, use: SDR.exe /i filename.rwd --details-- http://www.nrgsystems.com/FileLibrary/e510393a87c246648084d1cb79bf571e/ANSymphonieAutomate.pdf Silent Import Mode: Format: SDR.exe /i filename.rwd This mode is identical to Silent Batch Mode, except that in addition to converting the file to a .TXT file, it will be imported to the Site Database.
  16. Hi Matt - here are the details... Since the /S functionality of SDR is unattended,any event that requires user interaction is ignored. Instead SDR will create a .log file in the ScaledData folder containing an alert. In thecase of an unprocessable file, no TXT file will be created and no data will be imported. In cases such as a sensor update flag, data will still be imported, andboth the TXT and LOG file will be created. The bottom line is that when creating an automated system care must be taken to alert the operator on the creation of .LOG files. I would suggest that the .LOG alerts alerts are "pushed" to the operator by your automation engine (create and send an alert email with the log file contents) if possible. Even with an efficient and automated process, human intervention may be required. Thanks
  17. Hello, What are good applications for the new 95" boom? I was thinking about using it on a standard 60-m tower instead of the 60" boom. Looking at a tower shadow sketch, I see that getting a sensor only four tower diameters away from the tower would give a reading of at worst +/- 2% of free stream. For a 10" tube, that's only 40", and the standard boom is 60". So even if I were trying to get very clean readings at 10m AGL (on the 10" part of the tower), the 60" boom would be fine for every circumstance except for when the sensor is directly downwind (when you're screwed no matter what). Best regards, Alex DePillis --- The short answer is that the new 95 inch boom can be used in applications which require lower measurement uncertainty than the 60 inch boom. As for the long answer... I believe you might be looking at Figure G.5 in IEC 61400-12-1 which is based on 2 dimensional Navier-Stokes computations. If so, the figures you indicate are about right (4 tower diameters equates to about a 2.3% centerline disturbance). Another consideration is that the IEC model measures the offset distance as tower centerline to sensor centerline, which really places the 60 inch boom at about 6.5 diameters (for a 10 inch tower) equating to a centerline disturbance of about 1%. However, here is another way to look at it...what level of disturbance is acceptable for your wind resource assessment campaign? Many in the industry would say "let?s make it 0.00%!"... Basically, the further the sensor is away from the tower, the lower the disturbance. In reality, the law of diminishing returns comes into play and no matter how long a boom is (realistically) the disturbance will not (in theory) be 0.00%. At about 10 diameters, the disturbance curve flattens out and approaches horizontal. This is really the sweet spot of boom design as the centerline disturbance is less than 0.5% (some might say it is about 0.3% but I prefer to be a bit conservative). I have also heard that some in the industry believe disturbances are actually greater than what the Navier-Stokes model predicts. If anyone has seen research papers in this area, please add links to this thread! Of course, other design factors are involved such as robustness, cost, ease of installation and transport (the new booms are cost effective, easy to install and are also UPS shippable). In summary, NRG will continue to offer both the 60 inch boom and the 95 inch boom. The new 95 inch boom can be used in applications which require lower measurement uncertainty than the 60 inch boom.
  18. Also - I've created a new thread to discuss mounting boom choices under "Sensors and Mounting Booms"...please use that area to continue any discussion about mounting booms. Thanks!
  19. Great Question! The short answer is that the new 95 inch boom can be used in applications which require lower measurement uncertainty than the 60 inch boom. As for the long answer... I believe you might be looking at Figure G.5 in IEC 61400-12-1 which is based on 2 dimensional Navier-Stokes computations. If so, the figures you indicate are about right (4 tower diameters equates to about a 2.3% centerline disturbance). Another consideration is that the IEC model measures the offset distance as tower centerline to sensor centerline, which really places the 60 inch boom at about 6.5 diameters (for a 10 inch tower) equating to a centerline disturbance of about 1%. However, here is another way to look at it...what level of disturbance is acceptable for your wind resource assessment campaign? Many in the industry would say "let?s make it 0.00%!"... Basically, the further the sensor is away from the tower, the lower the disturbance. In reality, the law of diminishing returns comes into play and no matter how long a boom is (realistically) the disturbance will not (in theory) be 0.00%. At about 10 diameters, the disturbance curve flattens out and approaches horizontal. This is really the sweet spot of boom design as the centerline disturbance is less than 0.5% (some might say it is about 0.3% but I prefer to be a bit conservative). I have also heard that some in the industry believe disturbances are actually greater than what the Navier-Stokes model predicts. If anyone has seen research papers in this area, please add links to this thread! Of course, other design factors are involved such as robustness, cost, ease of installation and transport (the new booms are cost effective, easy to install and are also UPS shippable). In summary, NRG will continue to offer both the 60 inch boom and the 95 inch boom. The new 95 inch boom can be used in applications which require lower measurement uncertainty than the 60 inch boom.
  20. There is an excellent report by Frost and Sullivan that explains the differences (see link above). NRG Satellite iPacks use the Iridium network. frostreport07.pdf
  21. Yes - NRG makes a "Telus only" version of the CDMA iPack for use in Canada. See: http://www.nrgsystems.com/sitecore/content/Products/4224.aspx?pf=SymphonieCommunicationModules
  22. See the example PDF above... The extension of each bar in the wind rose from ?inner circle? towards ?outer circle? represents the percentage of the time the wind blew from those various directions. The outer circle percentage indicates the amount of relative uniformity of the wind direction. For example, if there was a very strange site where the wind only blew from one direction all the time, and never from any other direction, there would be a single bar going out from 0 to 100%. Most sites, however, have more scatter with wind directions distributed among numerous directions. All of the bars extending out will of course add up to 100% of the time period that was measured. The ?outer circle? value is intended to provide some context for the graph so that at a quick glance, you can tell that at the site below, almost 30% of the time, the wind direction was southwest, another 25% or so was north, and then the rest of the directions are distributed among the other directions to add up to the remaining 45%. windrose-sample-report.pdf
  23. A blue dot means the NRG #40C anemometer generator has been built to the new glue process (see TSB008) and has also inspected by NRG prior to calibration.
  24. The NRG Hybrid Turbine Control Sensors are now available! Contact NRG to learn about converting your existing turbine control sensors over to the Hybrid.
  25. The Symphonie Data Retriever Software can be downloaded from the Tech Support section at http://www.nrgsystems.com/TechSupport/SoftwareDownloads.aspx - Users can import data, scale data, export data and generate reports (windrose, frequency distribution, monthly graphs, etc.) for Symphonie, 9300, 9200-Plus, and Wind Explorer. - A chip reader function is included for 9200-Plus and Wind Explorer. EE Reader and DataPlug Reader can now be used directly with SDR. TermReader is not supported, but 9300 raw files read by BaseStation are supported. - Users can create, save and apply their own data filters to exclude icing data, faulty sensor data, etc. from reports. - Sensor history has been incorporated into the site editor for easier sensor changes. - DoCoMo, CDMA, and Satellite phones are supported in the iPack configuration module. - SMTP Authentication is now supported (requires a version 14 iPack). - POPAuto included: This utility program checks any POP3 mail account and filters / extracts Symphonie emails to the raw data folder.
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