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Good morning, I am trying to send a long number to a channel convert it to a string once received. The number, as an example, might look like this: field1=100630000553400000000 However, if I input it to a matlab analyze in thingspeak, i get it either as a number in scientific notation, or it is giving me a different number if I convert it using functions like mat2str, compose, num2str, etc. In the case of the number above, i get numbers like: field1=0100630000553399992320 It looks like the numbers are pretty close or there is some strange rounding going on. I am sending the field from a desktop mqtt server so the value is set by me. Is there something I should consider when sending such long numbers? Thanks! Reading long numbers in thingspeak Can you share your code to read the number (and perhaps your channel ID if it is public?) The key is when the string to number conversion is happening. I recommend keeping it a string at long as possible to keep the literal digits. Thank you for your help. The channel ID is 2221937. I made it public so you can see the message received. When I read your field 1 data, I see {"created_at": "2023-07-17T09:52:45-04:00","entry_id": 2,"field1": "100630000609200000099"}, Based on your criteria above, this looks like what you hoped for? Can you confirm if that is what you expect? Are you reading it into MATLAB and then printing there? Can you share the code youy use to read tha values? This is my code, i wil change the API key later. You can check the result register variables does not match what we can normally read using https://api.thingspeak.com/channels/2221937/feeds.json?results=2 % Enter your MATLAB code below % Channel ID to read data from readChannelID = 2221937; % Channel Read API Key % If your channel is private, then enter the read API % Key between the '' below: readAPIKey = 'VEMNQ70TRRNSVL1O'; format long registers2 = num2str(thingSpeakRead(readChannelID,'Fields',1,'ReadKey',readAPIKey),25) registers2 = num2str(thingSpeakRead(readChannelID,'Fields',2,'ReadKey',readAPIKey),25) registers3 = num2str(thingSpeakRead(readChannelID,'Fields',3,'ReadKey',readAPIKey),21) registers4 = num2str(thingSpeakRead(readChannelID,'Fields',4,'ReadKey',readAPIKey),21) registers5 = num2str(thingSpeakRead(readChannelID,'Fields',7,'ReadKey',readAPIKey),21) took me a little bit of futzing, but I got this: url='https://api.thingspeak.com/channels/2221937/feeds.json?results=1' kim=webread(url) registers1 = kim.feeds.field1 registers2 = kim.feeds.field2 ... also consider using thingSpeakRead with 'outputformat','timetable' when you want to read string type data. url='https://api.thingspeak.com/channels/2221937/feeds.json' btw, you dont need the api key if the channel is set to public. Thank you, Christopher! I will give it a shot today. I tried changing the output format but it was still showing as scientific notation. matlab long number string