Re: I pull fiftyfour bytes of data from MicroProcessor's EEPROM...
Hello, You mention that you send a string to the microprocessor that tells it how many bytes to send. Instead of requesting 512 bytes, try reading 10 times and only requesting about 50 bytes at a time. If that doesn=92t help, try directly communicating with your microprocessor through HyperTerminal. If you are not on a Windows system, please let me know. Also, if you are using an NI serial board instead of your computer=92s serial port, let me know. olliIn Windows XP, go to Start, Programs, Accessories, Communications, and select HyperTerminal./li liEnter a name for the connection and click OK./li liIn the next pop-up dialog, choose the COM port you are using to communicate with your device and click OK./li liIn the final pop-up dialog, set the communication settings for communicating with your device./li liType the same commands you sent through LabVIEW and observe if you can receive the first 54 bytes you mention. Also observe if data is returned from your 512 byte request or if HyperTerminal just waits./li/ol If you do not receive the 512 byte request through HyperTerminal, your microprocessor is unable to communicate with your computer at a low level. LabVIEW uses the same Windows DLLs as HyperTerminal for serial communication. Double check the instrument user manual for any additional information that may be necessary to communicate. Please let me know the results from the above test in HyperTerminal. We can then proceed from there. Grant M. National Instruments
Re: buffered digital output
Hello Thijs, The Port List connection of the DIO Config.VI should be wired with an array of the digital ports you wish to use. Each port has 8 digital lines. Unfortunately, the E-series devices do not support hardware-timed digital I/O. You could still output your points in a software loop, but you would not be able to guarantee 1000 Hz.For a card that does support this, look at the a href=http://sine.ni.com/apps/we/nioc.vp?cid=1104lang=US;6533/a. For further assistance in obtaining the correct board, go to http://www.ni.com and click on Contact NI at the top to speak with a customer support representative. Grant M. National Instruments
Re: Further Examples for the Picotech ADC200 Series
Hello Wayne, A good place to start for example code is the product manufacturer and it seems like you have already done that. National Instruments also provides example code we have created as well as from other users. You can search this library by going to http://www.ni.com and clicking on Support. In Option 3, click Example Code and you can search there. Another option is to search the instrument driver network for your hardware. You can search the instrument drivers by clicking Instrument Drivers from Option 3 of the support page. Then either click Download on the left hand side, or Search Drivers under Top Downloads. Instrument drivers often come with an example VI which shows how to use them. Unfortunately, it looks like neither place has any examples for your specific product. We are unable to provide examples for every product. However, if you'd like, you can click the Driver Request link on the instrument driver page. If enough requests come in for a particular product, we will create a driver for it. Good luck in your application development. Grant M. National Instruments
Re: where can i find additional DDE resources???
Hello, Dave has posted a couple of example programs which use DDE in LabVIEW. You can find a tutorial by going to http://www.ni.com and clicking on Support. Under Option 3, search Tutorials/Application Notes and enter DDE LabVIEW (without quotes) into the keywords box. One of the first links that will appear is Using DDE in LabVIEW (Windows Only). It is a tutorial which introduces DDE and LabVIEW. You can link directly to it a href=http://zone.ni.com/devzone/conceptd.nsf/webmain/14134D7CE042EDBF86256A3A006BD87C?opendocument;here/a. LabVIEW also ships with a couple of DDE examples. In LabVIEW 7.0, you can find these by going to Help, Find Examples. In the Browse tab, select Task and navigate to Communicating with External Applications and then to Dynamic Data Exchange (DDE). If you are using a different version of LabVIEW and unable to locate these examples, please let me know. The DDE functions are no longer in the palettes as of LabVIEW 6.0. You can still find them in Program Files\National Instruments\LabVIEW 7.0\vi.lib\platform\dde.llb. However, we recommend that you use ActiveX instead of DDE. There are quite a few examples for using ActiveX in the Example Finder under Communicating with External Applications and then ActiveX. You can also find an introduction to ActiveX by searching the Tutorials and Application Notes like above. Searching for ActiveX LabVIEW (without quotes) will return a link to a tutorial named ActiveX and LabVIEW. A direct link to this document is a href=http://zone.ni.com/devzone/conceptd.nsf/webmain/5401BE584FBAEECE862567C2006D36C7?opendocument;here/a. If you need to use DDE, see if these resources will provide the background you require. If you are flexible, try using ActiveX as it is simpler. Feel free to post again if you have additional questions. Happy coding, Grant M. National Instruments
Re: I pull fiftyfour bytes of data from MicroProcessor's EEPROM...
Hello, Can you elaborate what you mean by the system is lost? Ben has suggested a good idea of posting the code in question. It would also be helpful to know which version of LabVIEW you are using and which serial VIs you are using. His clarification of the timeout for the serial read is also a good suggestion. You mention that you have a 100ms wait statement. Is this in-between when you write the command and read the response? Sometimes the hardware needs a small amount of time to respond to the command. Putting a small delay between writing the command and reading the response allows the instrument to respond. If you have this wait statement here already, try increasing the wait time. Another option is to add a call to the VISA Bytes at Serial Port property node. This will allow you to check if data has been returned from the device yet or if there is an error with the command you sent. Try incrementing the wait time before reading a response and checking how many bytes are at the serial port. If they do not fix the problem, please post all or a portion of your code so we can get a better idea of the problem. Grant M. National Instruments
Re: can i use a counter input for a encoder feed back reading i 6014 daq card
Hello, Yes, it is possible to read encoder inputs with the 6014 card. In order to find more information about using encoders, ol liGo to http://www.ni.com and click on Support at the top./li liIn Option 3, under search select KnowledgeBase and enter encoder (without quotes) in the Keyword box./li liThe first link returned should be a href=http://digital.ni.com/public.nsf/3efedde4322fef19862567740067f3cc/c6c6632a54dba7dd86256275005e18e2?OpenDocument;How Do I Use a Quadrature Encoder with My Data Acquisition Board?/a./li /ol That is a brief tutorial about using a quadrature encoder. The example provided uses Traditional NI-DAQ. See below for finding an updated example using DAQmx. For more information, follow the link at the bottom of the tutorial page, a href=http://zone.ni.com/devzone/devzoneweb.nsf/Opendoc?openagent36BD71244BB26FC886256869005E541B;Using Quadrature Encoders with E Series DAQ Boards/a. This a href=http://digital.ni.com/public.nsf/3efedde4322fef19862567740067f3cc/eca86b184ef3b88086256c240067109c?OpenDocument;document/a describes the differences between the 6014 and the E Series boards. Since the pinout for the 6014 and the E Series boards is the same, you can follow the tutorials for using quadrature encoders with E-series boards. The user manual will be helpful in listing the pinout for your card. To find the manual, ol liGo to http://www.ni.com and click on Support at the top./li liIn Option 3, click Product Manuals./li liUnder Search, enter 6014 in the Additional Keywords box. A link to the a href=http://digital.ni.com/manuals.nsf/websearch/7FCCC893F141E3F586256C5A006CDDF9?OpenDocumentnode=132100_US;NI 6013/6014 User Manual/a will appear. Appendix B lists the pinout./li /ol Numerous examples ship with LabVIEW for illustrating various concepts. To find an example, ol liIn LabVIEW, go to Help, Find Examples./li liOn the Browse tab, select Task./li liOpen the Hardware Input and Output folder./li liOpen the DAQmx folder./li liSince the encoder is read through the counter, open the Counter Measurements folder./li liOpen the Count Digital Events folder and then open the Count Digital Events.vi./li /ol This example will provide an outline of what is necessary to read the encoder. Happy coding, Grant M. National Instruments
Re: In-place array subset replacement
Hello, Dennis is correct; a local variable will force a copy of the data. In general, LabVIEW will try to do an in-place replacement whenever possible. However, depending on what is happening with the data before and after the replacement, LabVIEW may make a copy. A good KnowledgeBase discussing buffer allocation is a href=http://digital.ni.com/public.nsf/websearch/C18189E84E2E415286256D330072364A?OpenDocument;Determining When and Where LabVIEW Creates a New Buffer/a. There is a small utility at the bottom of the page that will show you where data copies are happening. It sounds like you've been able to solve your problem. If you have any further questions, feel free to post again. Grant M. National Instruments
