use reference trigger for cyclic recording data

[HW_Autodesk]

Hi,

Before I start, let me briefly introduce what hardware I have and what I want to achieve.

 

I  got SCXI-1000 (Chassis), SCXI-1102C (module), SCXI-1303 (terminal block,

 

mainly for temperature sensor input); a couple month ago  I bought feedthrough SCXI-1180 and terminal SCXI-1302 to input my digital signal (see attached PNG file). In fact, I have two digital signals to input. The first one is Injection digital signal (input as PFI0) which will trigger the start of recording my

temperature profile; The second is packing signal (input as PFI1), which I want to use as a reference trigger to stop the recording and save as the cycle file.

And then the injection cycle keeps going. Please see the attached VI for details.

  

 I get my digital trigger working to start recording my temperature sensor profile. However, I can't get the second part trigger to stop the recording.

The error message from running my VI is that a reference trigger is only applicable for finite sampling. It seems that I need continuous sampling to recording my temperature profile! So, by looking through my VI, please give some suggestions to do the task and solutions to solve the conflictions for sampling.

 

Your assistance is higly appreciated.

HW

[jschwartz]

Hi HW,

One thing to try would be to configure your start task just like you are doing, but add another digital task that polls a digital line.  Whenever the digital line goes high, you can stop the loop, which will in essence be a stop trigger.

[HW_Autodesk]

Hi, Jim:

Thanks for the quick reply. I've tried successfully to add another digital task to poll a digital line (i.e. Port0/line7 from Pin 32 in SCXI-1302). But I've no idea about the steps you suggested:

1. how to add two tasks in  Task/Channels in Combo;

2. gain control to stop the loop if I like to use the digital signal goes low for my packing digital signal.

Would you please explain how to do above steps in more details?

Best Regards

HW

[jschwartz]

Hi HW,

 I have attached an example modified from one of the example programs that illustrates what I was telling you in the previous post.

[HW_Autodesk]

Hi, Jim:

I'm using LabView 8.5 version but your VI is in version 9.0. Will you please save it in V8.5 and post it again? Thanks.

Best Regards

HW

[jschwartz]

Hi HW,

Here is the VI in LV 8.5.

[HW_Autodesk]

Hi, Jim:

I've tried with the way you suggested to poll out the digital line. In your VI, it will stop the running of the whole program when the second signal jumps up. If you see my VI attached, I'd like to start recording with the first trigger and then stop the cycle file by the second trigger signal falls down, and then keep recording the second cycle until clicking stop (reference to my signal illustration).

So what I am trying is to use both trigger signal to output a boolean value (when both trigger signals are 0), reverse it to true (1), and use it to stop the cycle file. But I am still little far away from doing the task. Is there any way to do the cyclic file as I want with or without 'Write to Measurement File' VI?

Please edit my VI and save in V8.5. Thanks for your help! 

Best Regards

HW

[jschwartz]

Hey HW,

I don't think that you are going to need triggers but we can still poll the digital lines to figure out when to write to your measurement file.  I think that the best way to do what you want is to have a case structure with some logic before to determine when to write to your measurement file.  I have attached a VI that illustrates this concept. 

[HW_Autodesk]

Hi, Jim:

I got your illustrated idea work to pause and keep recording data. However, it is in the same file and can't stop the file to start a new recording file even I tried with 'save to series of files'.

Basically, what I am trying to do is that the program keeps running once started, and the second triggering will stop the logging file, plus a new file will start with next start trigger signal and this will keep on and on, which means the data will be recorded in series files, such as run1_cycle_001, & 002 etc.

I found the 'Write to Measurement File' VI can do either record/pause and append data to the same file or start a series of files without intervals. Even the way of stopping the file without 'Abort Execution' seems couldn't be done by this VI. Am I right about this? Any solutions as you know?

Your assistance is highly appreciated.

Best Regards

HW

[jschwartz]

Hi HW,

One thing you could try changing the settings in the Write to Measurement File to Use next available filename.