Saving values and exporting them into .csv

Chris D 3 years ago in IQANdesign updated by Gustav Widén (System support) 3 years ago 5

Hello everybody,

right now I'm working on a project wich requieres saving a lot of values and saving them in a .cws file.

I want to monitore around 10 different channels over a time span of around 8 hours on a frequence of around 100hz (= 100 values per channel per second). 

Additional i want to add a timestamp to each value. This needs to be kind of automated. In the best case i would want to push a Button on the display at t=0 and after around 8 hours later,i would push another button to stop the measurement, connect to the MD4 via Laptop, download my values and save them in a .cws file. 

I thought of something like a Measure group wich can be startet via the push of a button and wich saves the stored values and lets me export them.

I'm really gratefull for any help with this topic.

Thank you very much.


Timestamp [ms]Value1 [%]Value 2 [%]

I have to correct myself here, i'm talking about a .csv file of course.


I edited the topic title so it now says .csv 

You can easily export log files to csv with IQAN run.

You could make an event log with values that log every cycle if a timer is active.

8 channels * 100Hz * 3600 seconds * 8 hours = 23 million log entries.

The MD4 has enough memory for about 2,5 million entries.

Do you *really* need 100 samples per second? 

If you reduce your requirements you could use the builtin event log.

Otherwise I would probably use an external device (industrial computer or datalogger) connected via CAN-bus and send the data with J1939.

Thank you very much. Strangely the log only saves the value every 90ms. Even if i set the timer to 30ms. But this way is way better than everything else I have tried. Tanks you. 

With a very short log interval like that, the module will not have enough time to write to non-volatile memory.

The primary function of the IQAN master is the real-time machine control. The log function is designed to capture events that could come in bursts, but not really to perform continuous logging like a dedicated datalogger. 

When there is an event that should be logged, the IQAN master first puts information in a log queue. Then the log process then needs time to actually write it to flash.

You could measure on the system information channel loq queue to see the proportion of outstanding log requests.