Advice for Generic Controller and Test Machine in LabVIEW

[LVB]

I am fairly new to LabVIEW (6 months) and looking for a solution for test and measurement.  I prefer to use LabVIEW as the control system, but I cannot financially justify using LabVIEW.  There are a few types of tests that we run: state machines (wait for a certain set of digital inputs), ramping tests (increase output until certain input is hit), and position/voltage control (maintain a position/load/acceleration) and also log test data to a databeas.  I would like to create an environment where a user could “program” a test with ease.  We currently have the capability of a state machine with digital inputs, but lack the ramping and position/voltage control.  I was wondering if the community here could recommend some examples/solutions for this type of application.  Also, I was wondering if anyone has examples/resources that allow a user that has no LabVIEW experience to “program” this type of machine.  It seems to me that the development time for creating such a LabVIEW application greatly exceeds teach the user how to program PLC ladder logic and logging the information with a VB app over OPC.  However, I wish to use LabVIEW for the application.  Please respond with your advice!

Thanks,

Brian

[AnalogKid2DigitalMan]

Your post is confusing- you state you prefer to use LabView, but cannot financially justify using LabView. Are you looking for an economic analysis that may 'tip the scales' to justify the purchase of LabView for your application?

[LV_Pro]

As AK asks, what are you trying to determine. There have been some fairly lengthy threads on this forum regarding justification of LabVIEW vs. other environments, so you might search for those. As for LabVIEW vs PLC ladder logic, yes, there is a longer learning curve to learn to write programs in a full programming language than in a much smaller, limited environment like ladder logic. Of course you can do much, much more in the more complex language than in the simple ones.

Good luck, give us more info in what you are trying to accomplish and we can probably help.

P.M.

[LVB]

First, let me clear up and apologize for the confusion regarding finances.  I would like to create a flexible control system that can do the tasks listed below.  In reference to "finance", I was speaking of development time. 

I am fairly new to LabVIEW (6 months) and looking for a solution for test and measurement. There are a few types of tests that we run: state machines (wait for a certain set of digital inputs), ramping tests (increase output until certain input is hit), and position/voltage control (maintain a position/load/acceleration) and also log test data to a database. I would like to create an environment where a user could “program” a test with ease. We currently have the capability of a state machine with digital inputs, but lack the ramping and position/voltage control. I was wondering if the community here could recommend some examples/solutions for this type of application. Also, I was wondering if anyone has examples/resources that allow a user with no LabVIEW experience to “program” this type of machine. Basically to create an environment where the user could select certain steps in a sequence and have that sequence repeat, for example:

Step 1. Output the voltage on channel "n" to 10.0 V
Step 2. Wait for digital input "x" to turn on
Step 3. Increase the voltage on channel "n" at "y" Volts/Sec

[LVB]

Well, it looks like I scared everyone away.  This is not a PLC vs LabVIEW post.  It is meant to ask for assistance in creating a simple state machine that can be programmed from a simple GUI.  Anyone have some advice!

Thanks!

[AESulzer]

Brian,

Could you tell us a little more about specifically what you're looking for and what hardware you are talking to in LabVIEW? Generating a ramping value in LabVIEW is pretty simple, and in fact there are even ramping functions in LabVIEW's palettes. Once you have a value, all you have to do it pass it to your hardware driver, which will depend on your system. Rather than ask for pre-built examples, if you could ask a specific question or perhaps show us where you are stuck in your development, then I'm sure we could help!

Kind Regards,

[AnalogKid2DigitalMan]

Brian:

What version of LV are you using? There are numerous examples of state machines that can be searched for within the example programs that ship with LV under Help. There are also some on NI's site, including white papers that discuss various flavors of state machines. If you need more specific details, let us know.

[LVB]

I guess what I am looking for is an example of how to create a sequence of "states" in LabVIEW.  I was thinking that the application would involve a set of screens where you could create "n" sequences each with a set of digital/analog input conditions and digital/analog output conditions.

Taking a simple case of only digital IO, the user would be able to choose how many digital inputs to monitor for each state and what the resulting set of digital outputs would be.

This is very simple to do in a while loop with a state machine if you know what the states are ahead of time, but how should one go about allowing the user to create the states dynamically within a running LabVIEW application?

Examples:

Digital Inputs 1,3,5 are on -> turn on output 7
Digital Inputs 2,4 are on -> turn on output 5
Digital Input 3 is on -> wait two seconds, then turn on output 4


Any solutions, reccomendations, or advice would be appreciated!

[JLS]

Hello,

Here's an example of how to define and execute an arbitrary cycle.

I hope this helps!

Best Regards,

JLS