what is wrong with my setup?

[nicholas03]

I have this program....Trying to run this system. Why will it not work?



Message Edited by nicholas03 on 11-10-2007 09:29 AM

[Brian_Beal]

A little more information, please.  What doesn't work?  The hardware or the software?  Are you reading the temperature correctly?  Does the relay turn on/off?  What relay are you using?  What is the power source? It is best to check the hardware using the configuration and testing software that came with the USB-TC.  I think it is called InstaCal.  Do that first and get back to us.

[nicholas03]

It can read the temperatures and place the the temperatures into a table but the high and low limits dont work. This would make the relay not work. I don't know how to make the limits switch the relay.  The relay is 20mA .5A at 125VAC and has a 5V current. The power source is just a 9V, for example, a phone charger. Can you help?


Message Edited by nicholas03 on 11-10-2007 11:07 PM

[altenbach]

Who wrote the program?

There are a few things that don't make a lot of sense to me, but it is hard to decide without seeing the program live. 😉 Do you have some deocumentation of the hardware VIs?

• You seem to be getting an array of values, but then you try to built it into a waveform with the loop rate as dt. What's the logic behind that???
• If the high limit is exceeeded or the low limit is underrun, you seem to be writing the same bit at basically the same time. How should the hardware be able to tell what happened?
• ...

[nicholas03]

I wrote the program in hope of turning the light on so I could tell if the relay worked.  I do not understand if the wires are connected correctly in my hardware setup.  I also do not know why the switch in the relay is not being turned on or off by the exceeding of the limits.

[Dennis_Knutson]

You need to start with something simple. As Christian mentioned, it looks like you are sending the same value to the DBit Out function in both situations. Just write a VI with the DBit Out and write a one and zero. With the lamp disconnected, see if the relay opens and closes. If and when it does, connect the lamp and see if it turns on and off. If and when that happens, then go back to your other VI and see what might be going wrong.

[nicholas03]

Thanks, I will try it.

[Matthew_Kelton]

One problem you have is that your setting the state of the relay twice in the loop and using the same settings.  So, you are always goign to be setting the bit high and setting the bit low (assuming an alarm state exists).  The order of that is not determined as you have the VI's running in parallel.  You should OR the result of your high and low limit check and wire that into a single bit set VI.  You also aren't looking at the error code of that VI, so you may want to make sure you are also not generating an error there.


Message Edited by Matthew Kelton on 11-12-2007 12:31 AM

[nicholas03]

Can you explain any further please? I am still confused. What do you mean setting the state of the relay twice in the loop and using the same settings? I saw i was getting an error code but I do not know what to do with it.

[nicholas03]

I think I understand what you meant with the OR but it still is not functioning correctly. Do you see a reason for its malfunctioning?



Message Edited by nicholas03 on 11-13-2007 08:19 PM