Initial value shift register

Similar Questions

• Table/Shift register losing values

  Hello

  I have attached the VI.

  The vi has a table with values in them. Simply, it looks a number when this number of games, it moves on a column and add everything in that cell in a table. He continues to do this until he sees 'END' at which point she stops.

  The problem I have is that everything seems fine for the first two "values" after which no matter what additional value he acquired he loses everything and keeps only the last known value.

  Your current code takes the unique element of your table and makes a picture out of it.  You then insert the name Test.  So everything that precedes the family name went at that time.

  Here is the code updated the minimum which keeps the TABLE in the shift register and simply adds new test name in the table.

• Reset the shift register according to value

  Hey there ' All, I've been thrown in Labview to work, so I made a few minis and other programs on my own. The last one I wrote is a system of notification by e-mail, because it's something I plan use a lot. The idea is, I have a random number generator that collects a number every 100ms using a timed loop. When a number is greater than a certain threshold, say 0.5, an email is sent and a flag is hoisted. From there on, I don't want to send any other emails until the number is BELOW a certain level, say, 0.3. With what I wrote, I get emails to send no problem and I can't stop them sending (using a combination of Boolean indicator and a shift register), but I can't understand how to to reset the indicator to allow emails as soon as I "roll" a number under my lower threshold.

  Is there a way I can achieve this? I would be deeply obliged for any help. I have attached the VI I did below, apologies, if it is messy and so on.

  Use a Select statement after the structure of the case.  If the reset condition is True, then thread a real constant through the register shift.  If the reset condition is False, then just wire the existing through the register shift.

• Problem initializing shift register

  Hello

  I'm using labview 7.1 to control a spectrometer. In my program, I have a certain function that runs 32 times and adds up, and all works again n times. I use two 'loop' for s in the other. In the inner loop, I have a shift register to send information from one iteration to another, so that it adds. But I guess there is a problem with the shift register because I get just a blank chart after the loop runs. I used an indicator to check the output of the function, and it certainly works. I guess that the problem happens when I add up the results of two iterations. Sometimes when I would forget initialize the shift register that I use to have this problem, but this time I can't initialize the shift register because the option create a constant is disabled for some reason any. can someone help me please! Thank you!

  labview_dummy wrote:

  I'll try using a case structure and see if it helps.

  Seems to work very well here:

  

  labview_dummy wrote:

  I used the flat sequence structure because I donot want the spectrometer close vi to run before the loop that are parallel and not in series (they are all two cables to the first envelope and not to each other. Thank you!

  Can do "in series" by plugging the entrance in the loop FOR, for example.

• How to make shift register init happens only once, so that the data can persist across multiple tracks of a loop?

  Here's the situation:

  We are repeatedly followed eight real-world signals and comparing them to a threshold value.  We do this via a loop For inside a While loop.  The loop For runs eight times per pass.  We have implemented a binary table 1 d and the use of the index of the loop For as the array index, by putting a Boolean result in the table using the function replace table subset.  We want to keep the data in the table to be 'sticky', in the sense that any True value is locked, so even if a fake comes later, this array element true.  However, since we initialize the array in order for the replacement to the work table, we see that whenever the loop For again, it resets the table and destroys the history.

  I have attached a simple VI to illustrate the concept, using a random number generator as a stand-in for the real world signals.  How we change this VI do and entered real lock through multiples for loop runs, indefinitely?

  In case it is not obvious, I am a relative beginner, so please keep count in your response.

  Thank you

  B

  scottbbb wrote:

  For B, although I love the simplicity of it, I have a question: it solves the problem of the re-initialization?  What the shift of the While loop register get initialized - only once during its launch?

  Yep, the shift register Initializes only at the beginning.  You could say that every time the while loop is called (not each iteration) the shift register is reset with the wrong table.

  And, Yes, GOLD will always keep a REAL when it is TRUE.

  Usually, the simplest solution is the best.

• Store the Teststand ActiveX reference in the LV shift register

  It is posted here

  I'm trying to store the references TestStand ActiveX in a shift register not initialized a VI.  In my case, the references are passed into the TestStand VI (not created from in VI).  If I call the same VI to the next step (same sequence and execution of the previous step), since the shift register ActiveX references are not valid.

  The VI remains reserved to run during these two stages and is not unloaded from memory, so the shift register data should remain intact (in fact, the numerical values of the references are actually kept).  LabVIEW is still trying to close any ActiveX reference, even if they were not created from the VI?  Is there a way around this problem?  Or I'm just something wrong?

  

  jsiegel-

  In general, when the code is passed a COM reference and code is to keep the reference to a global or shift register, even after his return from the call, the code must add a reference to the object so that the object server knows that the object must be destroyed not. It is also the responsibility of the code that fits on the reference in the world or a register shift to release the reference to the object when it is no longer necessary.  LabVIEW is not different from any other language.

  So, here are more details. TestStand application LabVIEW for run the VI, TestStand after the reference as a parameter to the method of the server to run the LabVIEW VI. COM creates a proxy for reference and give the reference of proxy for the code module. Your VI then stores the value of the proxy reference in the global or the shift register. When your VI ends and returns to TestStand, COM releases the proxy reference, the value in the global or the shift register is no longer valid.

  Basically, you need to add or duplicate the reference to the object passed in LabVIEW by calling the VariantToData function. Pass the existing reference, set the input type to the same type of the reference, and the result will be the reference in doubles. You can assign the double reference to worldwide or register.

  Normally you must well to release the reference later by reading the value of the global or shift register, explicitly calling the function close reference with which to reference, and then assign A Refnum Constant stepped up to the global level or shift register to nullity. In the case of a module of code, I believe that when TestStand unloads the VI, LabVIEW frees the reference correctly. If this isn't the case, you will get a debug message to unpublished during the TestStand stop object if you have this option enabled.

• How to program the shift register to play only when a new user is detected user?

  Hello

  I'm currently developing a program of position control in labview. The program is quite simple, in which case the user will enter the distance on which he wants the table in the labview program and labview will send the signal to move a motor that will turn a ball screw to move a table horizontally to the targeted position. The criterion is that the profile of the engine depends on the distance to move, if a biphase (acceleration and deceleration) or three phase (acceleration, steady speed, deceleration) to reach the position of the target.

  The problem occurs when the user wants to enter a new entry second position) for the table, as the input by the user is the position that the table should be, but the necessary input to determine what profile the engine follows depends on the distance that the table moves to the target position. Therefore, I need a function to save the entry by the user temporarily and reminds that when a new user input is detected. Hereby, I would be able to use the difference of the input (input [n + 1] [n] input) and animal feed to determine what profile the engine follows and the entry by the user can be kept in the position he wants to the table to get (to compare with encoder).

  I thought to use for shift registers do, but I am not able to perform the deduction ([n + 1] - [n]) only when it detects a new entry. When I try to use registry to offset, it moves to the target location, and we only reached it will go to the original position. For example, when a user entry 90, this means that the table must be moved to the point 90. The shift register is initialized to 0, it will move to the point 90 (90-0 = 90), but arriving at 90, the shift register sends a signal of 90 (90-90 = 0) and the table back to its original position.

  Is it possible that I can delay the reading of the shift register only when a new entry is detected or there at - it another way for me to achieve what I want?

  I tried searching the forum site and neither discussion but could not find similar problems. Thank you for your help in advance.

  As I understand it, the use of shift registers with a structure of the event (to detect a user event when the user enters a new value) should solve the problem. Do not forget to post your request (or a version of it that isolates the issue) when you arrive at the lab, if we can get a clear visual of the issue you are facing.

• Change the shift register

  I hope someone can direct me on that. I'm stuck.

  The NTC, I want that it start at zero, enter the nested loop

  and when the case statement is equal to one, add 3000,

  so I have a lag on "undesirable" elements in the 1 d

  table I'm parsing...

  TIA!

  the nested loop shift register is not initialized, it is best to initialize it with a constant 0

  Then, the index entry Array subset function is connected after or before the function incriment? I can't decide...

  in any case, if it is connected before the incremint function then the nested loop iteration 1 will send a 0 at the entrance to the function of the subset of the Array index.

  EWW! , a lot of entries, words of functions in the above paragraph lol , can u get me here?

  now I can just understand the problem what exactly you're talking about. the sequence of events for your code will be like this:

  After the nested loop is complete, the output will be available (1 d the function add array element table) to the structure of the case where you want to add 3000 to the value of the shift register and start the loop nested with initialized again records with value = 3000? Am I wrong?

  If I'm right, you must reset the shift by using a control register, create a local variable to him and place it in the business structure then her manipulate it as shown below:

  

  Since the default data of "N" type digital command value is 0, then initially the shift registers will be initialized with 0 as the guy above

  Thank you

• Functional Global Variables: an indicator can be used instead of a shift register?

  It is a simple question, but I can't find an answer to it. The model agreed to a functional Global Variable is to use an uninitialized as in this example shift register:

  

  ('Référence IN' and ' Reference to "is actually a pile of references.) There is also a "Se Refnum" case, which comes the straight through the tunnels shift register.

  My question is, why can't we do store the indicator data? It is much simpler to use a shift register (IMHO a non obvious way to store global data!):

  

  The case "Se Refnum" does absolutely nothing. Other functions such as erasure of data can be implemented just as easily. The advantage of the FGV to help avoid race conditions is maintained because you always use the VI to access the data.

  JonP says:

  
  

  Not so much, the Inidicator can happily live outside the case structure, together and Clear would be just assign different values.

  If you have only a case structure, the indicator could not live outside of it.  In order to maintain the indicator data, your design requires that it is not written in for a case of Get.  If you have an exterior structure deal that decides on 'Get' or 'set or clear' and (in the case of "Set or clear") contains the terminal of the indicator and a classiquee case that decides on 'Set' or 'clear '.  However, I would consider this a design below using the standard template of the FGV.

  The difficulty with retrieving the value if you want to do a read operation / writing change. But LV provides many ways to retrieve data from an indicator (one you don't mention is the 'Value' property), do you mean that's all "incorrect"?

  Yes (I mean that they are all incorrect).

  You could hack your way around the design to work with a single structure of matter and the terminal of the indicator being outside using a method to read the value of the indicator and through a tunnel to the structure of the case through wiring for the tunnel of writing indicator in the case of 'Get '.  However, who will require a local Variable or value of property node.  As I said, these (I only mentioned the local Variable originally) are not good choices for performance and scalability.  If you are not aware of the functional differences between the terminals, local Variables and nodes of property value, refer to this article (obviously advantages/disadvantages such as redraw objects on the front panel are not relevant here).

  I guess you could say that indicators should only be written, but it is difficult to be pure!

  No, it's not, just use the classic design of the FGV!

• problem with the shift register

  for purposes of simplicity, I remove code without problems

  Description:
  1. my state machines, for some reason, a lot of cases.
  2. the order of each case may not change.
  3. the main prupose is to get the difference as on the front panel
  4. prior to entry difference, I first is measured in the case where 2 and TRY using shift register to pass data, ideally at least 5
  5. However, the "previous" value is updated too soon, unlike 'get' is always ZERO.

  for example
  You can see the shift register on the left side has two components, ideally, the 'get' difference should display 2-0 = 2.
  However, given that the second element of the registry team updates too early, my objective cannot reach and meet up with ALWAYS 0

  I think it's my misuse of the shift register for the computer to several cases.

  I pasted this problem for 4 hours... kind of stupid, but could not understand

  in a mulit-case state machine, how to properly passes data to the case (5 in this example) INSTRUCTION to ensure that I get the correct calculation

  GOLD: because I am only looking to the current value and the previous value, are there other ways to get this problem is?

  Thank you

  It is a case where execution highlighting can be helpful. Turn on execution highlighting by clicking the light bulb on the block diagram toolbar. Then, run the VI.  You will see the left side of the team to register the change as the state machine goes through States 3 and 4.  At the time where what happens to 5, all data in the change record is identical.

  One of them might be to use two registers to offset, one for the current value and the other for the previous value.

  Lynn

• Shift register

  Hi all

  

  

  This is my block diagram and front looks like.the given, I received are spectrophotometer UV, using RS232. FYI, there is no error with the spectrophotometer design.readings cannot be read by LabVIEW.the problem now is that reading spectrophotometer read only read to a time.here is the principle of operation of the spectrophotometer.note IM using spectrophotometer to measure the absorbance of the chemical solution.

   

  
  

   

  as u go push support for the sample on the position 1 to 4, the data will appear on labview.the 1-4 sample solution is different.so, I want to show all the data at once for comparison. such as display them on the Microsoft graph chart and data will be saved on im always new excel.since with labview, I have no idea how am I supposed to do.

   

  or maybe you have an idea or suggestion?

   

  as an attachment, I also tried shift register, but the result will display the same value on all the indicators.how should I do to read the data and display them one by mean of one.which in position 1, after the displayed result stop us the process, then switch to position 2 and visualize the data.and it continue until position 4 at the end show us all the data in a graph or chart.

  your help is greatly appreciated

  If you use the manual sample positioning you can take one of the solutions, we have provided and add the following.

  Place the code we have provided inside (flat or stacked) sequence and add a frame before it.  In this new context, add a while loop that has a button connected to the termination of the Terminal.  Essentially, the code will sit and wait until you press the button to take the measurement. (You can add a timer wait small to reduce the use of CPU, let's say 50 or 100 ms).

  Note that this is a very raw solution as long as the treatment is inside this loop until the button is pressed.  This prevents any other code to run.  The event structures are more robust.

  If you want to automate this process, a motorized linear actuator would work well (although probably not worth it for 4 measures).

• Increment of the counter without using the shift register

  Is there a way to count = count + 1, with using a node registry or feedback shift?  I have a structure of the event within a while loop (see table).  When the button is touched (kickoff event), a test is carried out.  Based on the test in the case of a string is passed outside of the event to a case statement of success/failure.  The user can run one of these 'events' as many times as he or she wishes.  And in an order any... Test1 (fails)... test 1 (fails)... again... test1 (go) again... test 2 (pass) then test 1 (pass).  When the stop button is reached, I would like to know how many times each pass/fail is produced for each test.  Try to stay away from shift registers, as I have 18 w key so a possible failure for each, so I would need 36 shift registers.

  In my example, the printed final statement would be:

  TEST PASS/fail # x test was performed

  test1 failure 1

  2 in case of failure test1

  Test1 pass 3

  Test2 pass 1

  4 passes test1

  etc.

  Do not see an attachment.

  You can use a shift register to store a table.

  Each button would be mapped to an array index. For each button pushed you the value of the index table, + 1, replace the array element and pass out back for the shift register.

• Shift register Alternative

  Hello

  I try to have my program permanently store the last several minutes of data that my sensor collects and run a calculation to see if a certain fraction of it is greater than a threshold. What I know, I could store the values in the shift registers, but I put on a hundred of thousands of values and who will get to clumsy on my block diagram and I was wondering what were the best ways to store these values.

  Thank you for your time.

  endlessOranges wrote:

  The probe should collect samples at a frequency of 1 kHz and I want to store the values of the last 593287. I'm looking in the tables store the values in the shift register, but I'm still pretty new with programming in this and are struggling to find a way that doesn't involve manually by dragging a lot of boxes to specify each index in the table to store values in.

  Simply use the data queue PtByPt .  It does everything you want.

• What is a simple way to explain a shift register?

  I'm having a technical assessment tomorrow and I need to know what would be the best way to describe a shift register.

  Hi peanut,.

  a shift register passes a value of an iteration of a loop to the other...

• A shift register reset

  Hey guys, I'm trying to get the my VI to zero out / clear the values of registry update once I reached a certain goal without having to restart my VI. I go where after so many cycles (defined) have been ran, my default data button (off). I want to be able to support this key data to acquire more data if needed... but my problem is that the shift register is the previous account! If I can get my shift register to clear to 0, I think I can move on to the next phase of my program. Yes, it is for the love of vanitys, but nevertheless, wanted.

  You can use a state machine. You have two States: perhaps slowed down and running? I've attached an example.

  You can reset your meter when the condition is fulfilled (in the transition state) without stopping the program. I hope this helps.