Serial Port Monitor to turn off Hardware

[MAXD]

All,

We have a test  Than needs to run independently and sometimes without Engineer's presence. It has a 5Kw Heater and a whole bunch of controls and transducers. The problem is we had that 5Kw heater overheated twice already. We do have a LOVE controller independently from LV installed but we need to keep all IO OFF  in case the LV crashes. I know it is a known issue with LV. 

I've tried Watch Dog but 7288 Chasse does not support it.

I need something that monitors the Ethernet com and then shut off a relay or something in case that com is down. I might be wrong on it but is there a device I can just purchase? 

See attached picture.

[GerdW · Accepted solution]

Hi MaxD,

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@MAXD wrote:

I need something that monitors the Ethernet com and then shut off a relay or something in case that com is down. I might be wrong on it but is there a device I can just purchase? 

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I can recommend this one, you can set a timeout parameter for the communication port and the device will react on this timeout event…

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@MAXD wrote:

we need to keep all IO OFF  in case the LV crashes. I know it is a known issue with LV. 

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Why is it a "know issue with LabVIEW" to crash?

[MAXD]

Hey,

here is the link to a thread where somebody is talking about it. Unless I don't understand something but even when you just stop the program your IO remain in whatever state they were left. They do not turn off.

https://forums.ni.com/t5/LabVIEW/Reset-digital-output-state-on-labview-crash-end-task/td-p/3572574

[RTSLVU]

Whenever working with heating elements you MUST use a hardware over temperature shutdown device that is totally independent of your LabVIEW program or main temperature controller.

Don't learn this the hard way like I did! 

Even the most expensive thermal chambers like Thermotron and Wyse have a completely independent controller for safety limits that can shutdown the entire chamber independent of the main programmable controller.

[MAXD]

Well, as I mentioned earlier I have a LOVE controller installed and controlling the 5kw heater independently. I need another ENG control on the Ethernet communication to the DAQ. In case I lose connection to LV the daq would be turned off as well.

[billko]

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@MAXD wrote:

Well, as I mentioned earlier I have a LOVE controller installed and controlling the 5kw heater independently. I need another ENG control on the Ethernet communication to the DAQ. In case I lose connection to LV the daq would be turned off as well.

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I think your first mistake is to have an independently controlled heater.  Like above, you should always have a hardware solution for a runaway heater that doesn't involve software.  The last thing I would worry about is IO because if your system is hung to the point where the software no longer functions, it is highly likely you won't have control over it anyway.  A solution might be to have all your instruments on a power supply that can be disabled via a relay or interlock.

[MAXD]

1) my system has an independent controller ( read my original msg)

2) IO have to be considered.

3) I found a solution maybe some people will find it benefitual:

https://www.digikey.com/en/products/detail/controlbyweb/X-WR-1R12-1I-E/13414900?s=N4IgTCBcDaIBoFoDqA...

[GerdW]

Hi MaxD,

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@MAXD wrote:

3) I found a solution maybe some people will find it benefitual:

https://www.digikey.com/en/products/detail/controlbyweb/X-WR-1R12-1I-E/13414900?s=N4IgTCBcDaIBoFoDqA...

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What is this different to my suggestion before (apart from handling just one DO)?

I used the WuT57730 to control a 100kW heater apparatus: it will turn off every output when the master communication is missing after a configurable timeout…

[MAXD]

The difference is that I can buy it here in the US and get it here in 2 days.

Your suggestion is what I am actually doing. I appreciate your help with that.

I will try it when it gets here.

Thank you

[Frozen]

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@MAXD wrote:

https://www.digikey.com/en/products/detail/controlbyweb/X-WR-1R12-1I-E/13414900?s=N4IgTCBcDaIBoFoDqA...

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That link no longer works or doesn't work for me.

Who is the Mfg and what is the PN? Digikey PN might work too.