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Hi

I have an application on a v570 that records temperature data as trends to a SD card. Then I use "trend from SD" to display the stored data in a separate screen.

The problem is that "trend from SD" always shows the first trend that was recorded to the SD card, while I'd much prefer to first see the last recorded trend and then manually list back in history.

Another problem I have is that I use the option that the user can change the Y min and Y max values of the graph, but anytime the user changes one of these values the display goes back to the beforementioned first recorded trend, while I'd prefer it to stay in the trend the user was "zooming".

I hope someone can help me with these matters...

Bye,

Bostjan

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Hi,

I am not sure I understand your problem. When displaying a Trend from an SD card you are required to specify the name of the file. You can choose any Trend you want.

Also, you can use the Link operand to choose which Curve to display:

post-130-026342200%201308758412_thumb.jpg

If you need any further help please send your application to Support@unitronics.com and describe in detail how to simulate the problem.

post-130-026342200 1308758412_thumb.jpg

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My application is very similar to the example "V570_SD_Card_Trend_Read_Write_Append.vlp" and the example has the same problem.

Let's look at the example "V570_SD_Card_Trend_Read_Write_Append.vlp":

I press Start Saving and Stop Saving a couple of times so I have more different trends. When I press View Trend the first trend to display is the first that was saved. If I want to see the last saved trend (the newest data) I have to press the button >> until I come to the end. When I'll have hundreds of trends stored it will take quite some time to find the last stored trend. I'd like to first see the newest trend and then go back in history by pressing the << button.

The difference between the example and my application is that in my application in the Trend from SD the user can change the min and max value of the Y axis. The problem is that when he does change this value the Trend from SD will "refresh", the min and max values of the Y axis will change but the displayed trend won't be the one the user was previously looking at but it will be again the first recorded trend. I want my user to search the recorded trends utill he finds the one that is interesting for him, then change the Y axis limits and direcly see the result witout the need to find the interesting trend again.

Bye,

Bostjan

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Hi Bostjan,

This is the way the function works now. I don't want to define it as "wrong". I'm sure there wil lbe users, which will prefer this order. Anyway, I'm takeing your idea in consideration. I'll see with our R&D what can be done to improve the funcikton in this matter.

BTW - "hundreds of trends" within the same file?! This is really not good idea. Taking in mind, that you can keep up to 320 indepemdent files in one SD card, the right way is to keep different portions of data in different files! Option "append" is designed to prevent data lost in case, let's say of accident power failure.

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  • 3 weeks later...

Did you recieve some feedback from the R&D? Can I expect this function in the near future?

Another thing that I don't like in "Trend from SD" is that it is not possible to know the exact value of any point in the trend. As you can see in the attached picture i have ~45 minutes of recorded temperature displayed in one screen but the only real data displayed is the time of the first and last recorded temperature. I'd like to have the possibility to know the exact time and temperature of all the displayed points that form the graph.

We tried to make this by saving data as trends and datatables on the SD card and then read the data from the datatables and display it on the top of the trend graph (see attachment). The basic idea was to move through time with the << and >> buttons (the yellow ones on top of the screen) and display the two temperatures at that time in two frames (top right over the graph). The problem is that it seems that it is not possible to synchronize the data in such a way that the data from the datatables will coincide with the displayed trend???

All in all it will be much better if the option of displaying the exact value of the points in the trend would be implemented in the "Trend from SD" function.

I have seen two solutions for this issue in concurrent products:

- displaying the values of the lefternmost point of the graph and moving the graph left and right one point at a time with the buttons < and >.

- a vetrical line that crosses the trend graph, frames to display the temperature where the vertical line crosses the graph and two buttons (< and >) to move the line left and right.

I much prefer the first option and I think it would be the easiest to implement.

Please, consider these solutions. I am sure that many users would be happy to have this option.

Bye,

Bostjan

post-3259-032217100 1310627874_thumb.jpg

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  • 8 years later...

Hi 

I have the same problem. 

I use v1210 to measure temperature and display on trend.

Operators make more than 50 measurements a day that last 4 seconds. When temperature  rise above 500C trend start recording and stops after 4 seconds.

The program have second display for Trend from SD. When we want to see the newest recording we use forward, fast forward, reverse and fast reverse buttons that shifts records fast but not enough.

Is there system function that will show the newest recording because there are many recordings and we need hours to rewind to the last measurement.

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  • MVP 2023

Hi dtwbb, please do not do multiple posts about the same issue.  It just gets confusing on the forum.  In future, please just do one post describing all your needs and observations, if desirable as a follow on in a topic, and include links to what you have found elsewhere if useful.  I have left all of your current ones up for this time only.

Please also remember that posts do not get shown until moderator approval occurs, which can be some hours if all the volunteers on this forum are not active.

cheers, Aus

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  • 2 weeks later...
  • MVP 2023

@dtwbb - Ausman is not a Unitronics employee.  He, I, and most of us on the forum are volunteers answering these questions out of the goodness of our hearts.

 

7 hours ago, dtwbb said:

We have more than 50 of your PLC's working well but you need to work on your tech support.

Please look at the top of this web page - 

image.png.13ebf2c364af7f5384054d9f97090803.png

 

If you click there you will be directed to actual real and true Unitronics Support.

You can also send your request to support@unitronics.com.

You can also contact the the distributor you bought the product from and ask them to help.

Joe T.

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