BSL PRO Software Guide - Biopac

292 Part EQ: Can I use other software with the Biopac Student Lab PRO hardware? Can I use Biopac Student Lab PROsoftware to control other data acquisition hardware?A: No. The Biopac Student Lab PRO hardware was designed to work with the Biopac Student Lab PRO software.However, the BSL PRO software can read in previously acquired text files generated by the Biopac Student LabPRO or any other software.Q: I have a device that outputs an RS-232/RS-422 signal. Can I connect this to the digital I/O line?A: No. These types of digital output devices have their own communication protocols and are more complex thanthe digital pulses that the Biopac Student Lab PRO can accept as inputs.Q: I imported a text file and the time scale is wrong. What happened?A: When a text file is imported, the Biopac Student Lab PRO software assumes (by default) that the data wassampled at 100 Hz or 100 samples per second. This is arbitrary, and there are two ways to adjust this. Bothmethods involve calculating the interval between sample points. To calculate the sampling interval, you need toknow the rate at which the data was originally sampled. The sampling interval is calculated by dividing one bythe sample rate. You can adjust the sampling interval to the appropriate value via the File > Open dialog boxbefore the data is read in, or if the data is already present, change the time scale in the Display > HorizontalAxis dialog box.For instance, if 20 minutes of data was originally collected at 2Hz and imported as a text file, the software willinterpret this as data collected at 100 samples per second. To set the time scale to accurately reflect the data,change the sampling interval from 0.01 to 0.5 seconds per sample.To change this setting before data is read in, click the “Options” button in the File > Open> Text dialog boxand change the value in the Sampling Interval dialog box. To change the time scale after data has been read in,adjust the units per division in the Display > Horizontal axis dialog box. If the data are time-domain data, youcan adjust the seconds/sample interval at the bottom of the dialog box. This value defines the interval betweensample points, and can be changed to fit the rate at which the data was originally acquired.Q: I just filtered a waveform and now my data file is huge. Why is that?A: When any type of transformation is performed (e.g. digital filtering, waveform math), the entire waveform isconverted from integer format (two bytes per sample) to floating-point format (eight bytes per sample). Sinceeach sample point in the waveform now takes up four times as much space, the file should be approximatelyfour times as large. The Biopac Student Lab PRO software still saves the file as compactly as possible, andsince some of the information stored describes the time base, the file size will not increase by exactly a factor offour.Visit the online support center at www.biopac.com