BSL PRO Software Guide - Biopac

80 Part CEach time an acquisition is restarted, an append markerwhich the MP UNIT restarted data acquisition.is automatically inserted into the record showing the time atWhen Append is selected, the display mode is set to Chart or Scope, and at least one segment of data has beenacquired, the Overlap Segments icon is enabled on the Toolbar. The Overlap Segments display mode overlaps appendedsegments of data. See Overlap Segments, page 640.Although you can pause for any period of time, the Biopac Student Lab PRO will only acquire data for the amount of timeindicated in the Acquisition Length box.Data can only be acquired in Append mode while being saved to PC memory.When used in conjunction with the external trigger, the Append mode can be a very useful acquisition tool. An acquisitionthat takes place over a long period of time with brief events which are few and far between can be set up in the followingmanner: the researcher watches for the events, triggers the acquisition to start, and then lets the pre-defined acquisitionlength run out. When another event of interest occurs, the researcher triggers the next acquisition. This acquisition will be“appended” onto the end of the first acquisition. Memory is the only limit as to how many “appendages” can be added.3) PC Memory/Hard Disk controls where data is stored during an acquisition. The best choice depends in large part on thenature of the acquisition itself and the type of computer being used.‣ PC Memory will store data in computer memory (RAM) during an acquisition. After the acquisition isfinished you will have to select Save As... from the File menu to permanently save this to your computer’shard disk. This usually allows for faster acquisition rates, although most computers have less availableRAM than disk space.‣ Hard Disk will save data directly to the computer’s hard disk during an acquisition. Hard Disk mode isfast enough (in terms of maximum sampling rate) for many applications, especially when only a fewchannels are being acquired. Saving data to Hard Disk allows for longer acquisitions, since mostcomputers have more hard disk space free than free RAM. An advantage of saving data directly to disk isthat if there is a system failure (including power outage), all the data collected up to that point has beensaved on the hard disk and can be recovered, whereas data saved to PC Memory would be lost.— IMPORTANT NOTE —If you are saving files in Hard Disk mode, always be sure to save files under a different name BEFORE you start eachacquisition. Otherwise, any previous data in that file will be overwritten. In PC Memory mode, you simply go through thestandard procedure of saving the file after the acquisition. Once data has been acquired and is stored in a file, it is stored ona hard disk or other similar device.Visit the online support center at www.biopac.com