BSL PRO Software Guide - Biopac

112 Part CThe Control function is used to output a digital pulse when the value for a specified input channel exceeds a certainlevel, falls inside a given range, or falls outside a given range. This feature is unique in that the output is on a digitalchannel (which ranges from I/O 1 through I/O 8) rather than a Calculation channel. Also, unlike other Calculationchannels, this Control Calculation can only be performed in real time (i.e., while data is being acquired) and cannotbe performed in post acquisition mode.In addition to outputting a signal on a digital channel, the Control Calculation will also plot an analog version of thedigital signal on the Calculation channel you specify. For instance, in the example below, Calculation channel C0 isused to perform a control function using analog channel 1 (C1) as an input and digital channel 0 (D1) as an output.In addition to outputting a pulse on D1, the setup below will also produce a plot on channel 40 (the first Calculationchannel) that emulates the signal being output on digital channel 1. Since Calculations are analog channels, theCalculation channel does not contain a “true” digital signal, but is a reasonably good approximation. The calculationchannel values are not guaranteed to precisely match the actual digital output.To have BSL PRO apply a Control Calculation in real time:1. Choose MP3x > Set Up Channels.2. Click the Calculation tab.3. Check an Acquire box for the Calculation channel you want to contain the filtered data. You may alsocheck the Plot and Values boxes as appropriate for each channel.4. Click the Preset pull-down menu and select Control.5. Click the Setup button in the Input Channels dialog to generate the Control dialog.There are four parameters that need to be specified for each Control channel:a) Source channel c) Type of threshold functionb) Output channel d) Threshold level values“Source” refers to the input channel to be used for the Control function. As with other Calculation channels, theControl function can use either an analog channel or another (lower) Calculation channel as an input. In the previousexample, analog channel 1 (C1) is used as the input channel. It is not possible to use a digital channel as an inputchannel for a Control Calculation.The channel selected in the Output Channel section determines which digital channel the pulse will be sent to.The digital channels range from 1 to 8 (D1 through D8) and external devices can be connected to the MP36/35unit’s I/O port as described in BSL Hardware Guide. In the sample dialog shown, the digital pulse is sent over I/Oline D5.Visit the online support center at www.biopac.com