yoonengineer

Dear MCC Team, I hope this message finds you well. I am reaching out to discuss an issue I encountered while attempting to measure temperature using the USB-2408 device in conjunction with Matlab. Although I have successfully obtained voltage measurements through the data acquisition (DAQ) capabilities, I am unable to directly measure temperature values. Considering that temperature measurements are a common requirement in various applications, it seems counterintuitive that users are unable to utilize the USB-2408 device for this purpose. I believe that incorporating temperature measurement functionality would greatly enhance the device's versatility and usability for a wide range of users. Therefore, I would like to kindly request if it would be possible for MCC to provide a Matlab code that enables temperature measurements with the USB-2408 device. Such a code would be immensely beneficial to users like myself who rely on Matlab for data analysis and acquisition. Alternatively, if providing a dedicated code is not feasible, I would like to inquire if MCC could provide access to the cold junction temperature. This would allow users to develop their own custom codes to calculate temperature measurements based on the voltage readings obtained from the USB-2408 device. I sincerely believe that addressing this issue would greatly enhance the capabilities of the USB-2408 device and further solidify MCC's commitment to providing excellent user experience. Your support in resolving this matter would be immensely appreciated. Thank you for your attention to this matter, and I eagerly look forward to your response.

I am thinking mearuing a temperature every second. I am not familiar with LabVIEW, so I would like to use Matlab.

Thank you for your reply. Then, can I export temperature data from DAQami real-time? Or, is there any way to get temperature data to Matlab real-time?

I found the problem. I changed dq.Rate to lower, then, it worked. Thank you very much for your help. Would you mind if I ask you several more questions. 1. Would you provide any example of Matlab code that measures voltages from multiple channels? The current example code provided in MathWorks website only gets data from one channel. 2. I want to measure temperature, not voltage. If this does not measure temperature via Matlab, would you inform how I can calculate the temperature from the voltage measurement? 3. Would you inform me how I can get Reference Junction Temperature when measuring voltage, then, maybe I can calculate temperature out of the voltage measurement?

Thank you for your reply. I followed your instruction step-by-step. Matlab detects USB-2408. However, if I run "[data, startTime] = read(dq, seconds(1));", I got the following error message as before.

After installing Instacal 6.60 and connecting USB-2408, if I open Instacal, it does not detect the device. Do you have any idea how to make it detected? If I upgrade to 6.74, it detects the device. However, if I run "[data, startTime] = read(dq, seconds(1));", I got "Timeout expired before operation could complete" as shown as follows.

Would you inform me how you installed or upgraded to ver. 6.74?

I found this instruction before I asked. I did this steps several times, but didn't work. The problem is that it installs ver. 6.60, and it did not detect the device. Would you inform how I can upgrade to ver. 6.74 after installing 6.60?

Would you inform how you installed InstaCal ver. 6.74? I am confused because ver. 6.74 is not suppored by MathWork.

I followed your instruction. If I open InstaCal, I can see USB-2408 as follows. However, I got an error message as follows if I run the code in Matlab. If I type the "v=daq.getVendors" in the command window, I got the following message.

Thank you very much for your response. The current version of Instacal is 6.60. It is a bit complicated how I installed Instacal. I downloaded the support package from MathWork website and installed it. It is ver. 6.60. The problem was that it did not detect the USB-2408. So, I uninstalled it. Then, I downloaded from mccdaq.com and installed ver. 6.74. Then, I opened "C:\Program Files (x86)\Measurement Computing\DAQ" and copied the following files. After that, I uninstalled ver. 6.74 and re-installed 6.60, which I downloaded from MathWork website. Then, I pasted the following files to "C:\Program Files (x86)\Measurement Computing\DAQ". Then, it was able to detect the USB-2408. * The files that copied and pasted. ICalHelp.chm logo.bmp ReadMe.txt ReadMeUL.txt ULHelp.chm ulprops.txt

Hello all, I am tyring to use USB-2408 with Matlab. I just copied the following code from MathWork website. Then, Matlab displays as follows with an error message "Timeout expired before operation could complete.". I extended the seconds(1) to seconds(60), however, I got the same error message. I've searched/googled to find the solution, however, I could not find any useful information. Would you help to me fix this problem?

Hi Fausto, Thank you for the information and advice. I plan to use it for collecting temperature data in real time. So, thermocouples will be connected to USB-2408 and I would like to measure and record temperatures real time while doing experiments. Best,

Dear Sir or Madam, I purchased MC USB-2408 and I would like to use it using Matlab. However, I can’t find any information how to do. Would you give me any information how I can use this device using Matlab?