How to get the internal PLC temperature?

 I am also interested in a way to get the internal PLC temperature. We plan to use the PLCs for some outdoor applications powered by Solar power. This means that every extra device adds to the power consumption. It would be great to get the internal PLC temperature and use that to temporarily turn on a cooling fan

Pableras

Hello. I Arrive here llocking for possibility of reading internal temperature. And I find a post plenty of jokes.

Everybody has its reason to ask questions... Bosses sometimes have many time to think and not to much money to spend. So they ask for this kind of courious solutions. In my case I have a thermostat in the electrical cabinet that activates/deactivatse the fan. If fan breaks or somebody sets up thermostat to high, temperature woult increase and nobody would notice (no sensor). Project manager wanted to know if it would be possible to know this situation.

In OPEL Belgium (2004), they controlled PLC temperature. They received this value from Boch PLCs (big PLCs installed in small offices with air conditioner). If somebody switched off or left door open (door open stopped air machine), temperarture in PLC's increased. If it would be possible to get internal temperature in PLC, it would be an easy way to control that something wrong is happening..

 

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Split from Internal Temperature of S7300.

Hello,

this was everytime solved by other equipments independed to PLCs. You  mean that if PLC is in STOP that it doesn't produce higher temperature? Standards defines temperature ranges where then external system turn on some cooling system and this has independed temp sensor to do intervention in case. If you want measure internal PLC temp then from what places ? What place is most critical? This ismply depends also to actual place conditions and HW placed. Therefore this kind of service is set by independed HW system.

Hi,

as far as i know there is no function to read the internal temperature of the CPU.

But in principle is not necessary, especially for cooling reasons inside a cabinet.
In the technical documentation, there are statements to the maximum surrounding temperatures the CPU can be used with, the internal temperature is not the primary stat.
Furthermore, you have to check all equipment used inside the cabinet, maybe there is hardware with lower max temperature limit as the cpu. The max temperature of the CPU must not be the bottleneck in the scenario.

Turn on/off the cooling equipment, based on the temperature in the cabinet. Take the lowest max. temperature value of all used components.

regards

sancruz

Thank you all for your feedback. The question was asked by my boss hence the post on the forum.

We have run some tests on the system in very hot weather and there were no performance issues.

We also have another device that actually gives us internal temperature data which we can use for our tracking.

I still think that even if it looks like a useless feature.it may still be helpful for Siemens to provide this feature. Doesn't hurt to have 

Oladimgba

Thank you all for your feedback. The question was asked by my boss hence the post on the forum.

We have run some tests on the system in very hot weather and there were no performance issues.

We also have another device that actually gives us internal temperature data which we can use for our tracking.

I still think that even if it looks like a useless feature.it may still be helpful for Siemens to provide this feature. Doesn't hurt to have 

Come in contact with Siemens if you feel strongly about this subject. The fellow users on this user forum cannot do much for you in influencing design decisions. You can use the "Support Request" link. Or better - speak to your local Siemens representative. 

Did you know that Siemens has a range of products that can handle higher temperatures? 

Most (not all) thermocouple input cards have a cold junction (CJ) measurement sensor to sense the temperature of the terminal block, which for all practical purposes is the ambient temperature.   [The CJ is not the process measurement from the thermocouple, it is the measurement used to add to the thermocouple's mV gradient temperature to obtain the reported process temperature.]

On systems I install I monitor, log, and alarm on the CJ temperature because it does reflect the operating conditions where the I/O and the rest of rack is installed.   Using the CJ temperature, when it's available, does not use up an external I/O point with its remote thermocouple; the data's there without using an I/O point.

But this most likely just "academic" information, because the question about internal temperature wouldn't be asked if there was a thermocouple card available.