Monitoring and Alarming System for Blue M furnace

[Brian F.]

Hello brian1.  I am glad to hear that you are able to measure the temperature successfully. 

In regards to the alarm, I don't think we have hashed out what type of alarm you are trying to control.  Is it an external device that requires a high state voltage (i.e. 5 Volts) to be active and a low state voltage (i.e. 0 Volts) to be disabled?  Or do you simply want to have an 'alarm' in software represented as an LED indicator in LabVIEW?  If it is the former, this can be done easily by using a digital line on one of our data acquisition boards paired with our DAQmx driver to produce the high or low voltage needed.  If it is the latter, setting up a comparison of the temperature to detect if the temperature is above 300 degrees and then setting the state of an boolean indicator in LabVIEW would be the way to go.

Either way, I would recommend first setting up the logic with a boolean indicator in LabVIEW to prove to yourself that all of your programming logic is correct.  From here, you can then integrate an external alarm into your application if you desire. 

Let us know if you have any further questions!

Brian F
Applications Engineer
National Instruments

[brian1]

I just want to know whether we can run the alarm using the windows media player or anyother type of sound which can be generated from the computer.
Thank you

Brian

[Brian F.]

Hello brian1. 

You can output a sound using our Beep.vi.  This VI outputs a tone of user specified frequency and length via the piezoelectric device onboard your computer.  You can also use the Simulate Signal and Play Waveform Express VI’s which will generate a signal and output it on your speakers.  I would try these first.  You can output sounds via Windows Media Player, but this is a bit more complicated.

Have a great day!

Brian F

Applications Engineer

National Instruments

[brian@nandu@yahoo.co.in]

Hi Brian,

I can use any of the three options you gave me, I dont want to use anyother external hardware to generate the sound, I want to generate the sound from the computer when the alarm is enabled. so can you suggest me wih one of the good solutions.

Brian

[SamboNI]

Hi Brian,

As Brian F mentioned, the Beep.vi is probably the most straightforward and easy solution. It requires no external hardware (it is the onboard computer speaker) and is simply one VI. It can be found under Programming->Graphics and Sound in the functions palette on the block diagram.

Regards,

[brian1]

Thank You,

I have created this proram for the alarm system for a furnace, here the temperature ramps up from the room temperature to 300 degrees celsius( alarm is disabled at that time), once the temperature reaches 300 degrees, soaking starts and the alarm is enabled and if the temperature is out of range of the given limits to the setpoint temperature the Alarm is ON, Now I also want to include sound with the signal, as you have said in the previous posts I tried those but I am not able to figure, can you please modify my circuit which includes the sound signal.

Also if possible can you tell me how to disable the alarm once the soak period is over , soak period varies for different profiles.

Thank you

Brian

[brian1]

Hi,

I got the alarm to work by keeping the beep.vi in a seperate loop. The only thing I am stuck up with is disabling the alarm after the soak period.

Thank you.

Brian.

[SamboNI]

I don't think you need a second while loop in this application... How about instead, each time through the loop, you check to see if the soak period is over. If it is not over, you have the false case of a case structure contain beep. If it is true, you don't do anything (and you'll need to set the duration input of beep.vi appropriately).

[brian@nandu@yahoo.co.in]

Hi,
I am not able to disable alarm after my soak period is over.. can any one modify my cicuit.
Thank you

Brian

[SamboNI]

Hi Brian,

I don't think that I am underdstanding your application entirely... when the alarm is on, you are in a "soak period", correct? Assuming this is the case, then the beeping should only be occuring when you are in a state of alarm, as dictated by the boolean wired to both the alarm indicator and the case structure that contains the Beep.vi

So, as long as your logic is correct in early sections of the code to have the alarm be "ON", then the beeping should stop as soon as this boolean value is set false.