Programming a switch (make/break) in labview

[RandelPrandel]

Hello, 

I am trying to replicate a physical switch in labview. This switch is pressure reliant. i.e, when the pressure reaches a certain limit, the circuit in the switch is made and when the pressure goes down to a certain limit, the circuit is broken. The pressure is measured using a transducer with Voltage output. Also, the switch has a voltage output too. 

The way i am trying to represent it programmatically is given below,

When the pressure is ramped up to the certain limit, the circuit in the switch is completed (made) and a green light glows on the control panel. And When the pressure is ramped down to a certain limit, the circuit in the switch is broken and the green light turns off. 

One way i can maybe do this by having two DAQ assistants, one reading presssure and the other reading voltage; have the voltage data output through a case structure and have the light glow when the circuit is made. ---AND, simultaneously, display the pressure from the other DAQ assistant at this point. If this is the "simplest" and the "right" way to do it,  do i need to have some connection(relation) between both the DAQ asisstants so that the pressure value at that point of 'completed circuit' is displayed (?)  or can i run them independently and still achieve this? 

Can anyone share their thoughts on programming this? 

Thanks, 

RP. 

[apok]

We test avionic switches here and use LabVIEW to control lighting of the individual quadrants on the push button display. we test switch contact transfers for 4 poles double throws. we also test for reverse diode in circuit and contact resistances. for compression testing, we use an Instron

i would start by tying the commons to digital ground and the throws to the digital inputs. we are currently reading AI and Dig Inputs together in the same loop.

[_kb]

RP

You may find this related application helpful.

[RandelPrandel]

Hello Apok, KBreezy, 

I think that is exactly what i was looking for. 

Hardware: CDAQ, NI 9205 Module. 

The steps in need to accomplish to design the switch are as follows: 

1. Read input pressure  

2. For the switch (0 to 28 volts); when the voltage is 0 volts -> Display a red light. 

3. When the voltage is 28 volts -> Display green light and a message "PASS"

4. Display input pressure when the light turns green. 

5. Record data in a file. 

Can you share your thoughts on how to accomplish steps 2 and 3 ? 

I believe, i can use the Mask and limit testing VI to do this.  Is that right ?  

Thanks,

RP. 

[_kb]

If between 0 and 28 volts, the LED should be red, then yes -- you've got it!  You would just have to alter the properties of the LED on the front panel to set the on/off (true/false) Colors and Boolean text.

If you are looking for a 3-state LED, it's going to be a bit more difficult ...

[_kb]

[RandelPrandel]

Hey KBreezy, 

You are right. Between 0 to 28 volts, the LED Flashes red and when the switch outputs 28 volts, it flashes green. (2 state switch).

I made that change in the properties of the LED. 

Am working on a few other permutations on the logic and the Data acquisition part now. I will keep this post alive for further questions. 

I really appreciate the help. 

Thank you, 

RP. 

[RandelPrandel]

Hey Kbreezy, 

So, i got the LED part fixed and I have a question on the data acquistion part. 

I am using the report generation toolkit to generate a custom excel report from the acquired data. The problem i am facing is that the MS office report express VI does not accept the custom template that i've created. Any thoughts on why this is happening? 

I have a general template which I want to populate the data in and when i feed this template into the express VI, the report contents column remains empty and does not show the contents of template. 

Please share your thoughts on why this is happening.

Thanks you, 

RP. 

[_kb · Accepted solution]

Working from the Sample Report (Word).vi example, we were able to set up the functioning block diagram below.

It sounds like there are a few more aspects of your project to consider, RP.  For further questions, let's continue working on our open service request.