Clamp Stim Time Tab

Stimulus Modes

Continuous – no time between acquired data waves. Save While Recording is not allowed in this mode, nor any online analysis functions.

Episodic – waits an interlude time before acquiring each data wave. The interlude is timed by Igor (i.e. your computer) rather than by the DAQ device (see Epic Precise).

Epic Precise – same as Episodic but the interlude is timed by the DAQ device. Depending on your DAQ device, there is a limit to how long the interlude time can be. If the interludes are too long you will need to use Episodic.

Triggered – acquires waves after receiving an external trigger supplied by the user.

Time Stamp and Interval Waves

You can get a reasonable estimate of how well NeuroMatic is timing acquisition by editing the waves CT_TimeStamp and CT_TimeIntvl. These waves are saved inside the current NeuroMatic Data Folder. It is emphasized, however, that the time values are not exact as they are computed from starting and stopping a micro-second timer within an Igor function. If you are using Epic Precise acquisition, the actual performance of acquisition will be more precise than the values listed in these waves.

Stimulus Interface Menu

For NIDAQ users with more than one DAQ device, this drop-down menu can be used to set a different sample interval for each device. For example, one can generate a stimulus output waveform at a rate of 50 kHz with one device while acquiring data at a rate of 10 kHz with another device.

Waves

  • number – the number of output waves in your stimulus protocol, here denoted waveN. For example, if you want to create a current-voltage relation with 5 different steps, set waveN = 5. If you have only a single step which you want to repeat 100 times, set waveN = 1 and set 100 repetitions below (repN = 100). Do not use waveN to create the effect of repetitions as this may create an unnecessarily large number of stimulus output waveforms, resulting in less working memory for Igor as well as larger data files (stimulus output waves are saved within each data file). Note, stimulus output waves are numbered from zero. waveN defines the number of Groups, which is set automatically in the current NeuroMatic Data Folder.

  • wave length – the epic time to acquire (msec).

  • tstep – the acquisition sample interval (msec).

  • samples per wave = wave length / sample interval

  • interlude – time between epics (msec). Will be zero if using continuous acquisition, but must be greater than zero if using episodic acquisition. Note, if you are using online analysis, you need to set an interlude long enough to allow execution of the analysis. Interludes 500 ms or longer are usually sufficient, but it depends on how intensive the analysis is.

  • rate = 1000 / [wave length + wave interlude] (Hz)

Repetitions

  • number – number of repetitions (repN) of your stimulus protocol.

  • interlude – time between repetitions (msec).

  • rate = 1000 / [waveN * (wave length + wave interlude) + rep interlude] (Hz)