Problem with Thingspeak input block in simulink

problem in sending data from ThingSpeak to Simulink block. Everytime I tried to send data from write channel it is not showing the exact graph as in ThingSpeak visualization.

[Hans Scharler]

Are you setting the writekey and channel? https://www.mathworks.com/help/sldrt/ref/thingspeakoutput.html

[Tanusree]

Yes. But still some datas are missing.

[Christopher Stapels]

How frequently are you writing to the channel? There are some update rate limits.

When you say "not showing the exact graph as in ThingSpeak visualization." Do you meant he field plots dont match your ThingSpeak visualization or that the data in the ThingSpeak visualization does not match what you expect it to be?

[Tanusree]

The plot in my Simulink model scope doesn't match with ThingSpeak visualization.

[Christopher Stapels]

Can you clarify what you mean by not matching? Are the data points completely different, or are there just a few missing, or something else?

Maybe you could share a screen shot to show us what you mean?

Answer 1

[Swaraj]

Hi Tanusree,

The issue might be due to one of the following:

1. Please check that the channel number is correct and the Read API Key you are providing is correct.
2. Please check the "Update period" field. It is used to set the time between successive reads over the channel.
3. Verify the "Sample Time" of the block as well if it is as per your requirement.

For more information, please follow the below documentation:

https://in.mathworks.com/help/sldrt/ref/thingspeakinput.html

Hope it helps!!