Logging Signal Data to File
Accessible through the “Signal tools/Log data in file... or Data acquisition/Log data in file...” menu option.
Data acquisition operations can produce large amounts of signal data which cannot be stored in RAM. This function can be used in such cases to store all signal data from one data acquisition window in files on the hard-disk. Of course, this function can also be used for non-DAQ signals if needed.
Also, you can use this function for a long-time instrument values logging to a file. See Logging instrument values for details.
Recording in this window can also be automatically started from an Instrument window where the corresponding alert/trigger option has been selected. See Instrument Properties for details.
After choosing this menu option, the following dialog appears:
Target folder: Type or choose directory where signals should be stored. The directory should already exist.
File name prefix: To make file names recognisable, you can define a prefix string which will be added to the beginning of each created file name.
Create new file when file size of … (MB) has been reached: You can limit the size of a single file. After reaching the length you define here, SIGVIEW will create a new file and continue storing data in it. Maximal file size is 2047MB.
Stop automatically after recording ... seconds: You can limit a total duration of one recording in seconds. After reaching this duration, recording will stop automatically. Please note that input data blocks will always be saved completely, so that the maximal duration can be slightly exceeded for the length of up to one input block. MAximal value in this field corresponds to a one week, i.e. 7 * 24 * 3600 = 604800 seconds.
Wait for manual “Start” command: If you turn this option on, the log window will not start storing data after it has been created, but will rather wait on your command. You can manually start and stop the logging process by using the context menu (right mouse button) options in the logging window. Also, in that state, a recording can be automatically triggered from an instrument value. See Instrument Properties for details.
After you set all properties for signal logging and press the OK button on this dialog, the log window will appear:
It shows all information about the logging process, including current file, amount of stored data, recording duration, number of files and average data rate.
Signal files will be created in the target folder and named <prefix>_<YYYYMMDD>_<HHMMSS>.SIG.
To make data storage fast enough, data is stored in a 32-bit binary float format without any header information. The file extension will always be “*.SIG”. All additional data such as sampling rate or start time is stored in a *.txt file having the same name as the stored SIG file.
To load SIG files in SIGVIEW, use the “File/Open data log file” main menu option. This function will load the SIG file and automatically read its additional information from the TXT file. You can store your signal in WAV or any other supported format afterwards.