Stim Time

Stimulus Mode

Continuous – no time between acquired waves. Save While Recording is not allowed in this mode. Currently only available for ITC interface.

Episodic – waits an interlude time before acquiring each wave. Timing is performed by Igor, which can be imprecise. Use this mode only if you have long interlude times, i.e. several seconds.

Epic Precise – waits an interlude time before acquiring each wave. Timing is performed by acquisition boards. Depending on your acquisition board, there is a limit to how long the interlude times can be. Test your protocols before recording. If the interludes are too long, you will need to use the Episodic mode.

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

Time Stamp and Intervals

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 along with your data. It is emphasized, however, that these time values are only estimates, since they are derived 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 device, this menu option 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 (waveN), also referred to as the number of “groups”. For example, if you want to create a current-voltage relation with 5 different steps, set n = 5. If you have only a single step which you want to repeat 100 times, set n = 1 and use repetitions n = 100 below. Do not use this setting to create the effect of repetitions since it may create an unnecessarily large number of stimulus waveforms in NeuroMatic’s Clamp folder. Note, stimulus output waves are numbered from zero.
• wave length – the epic time to acquire (msec).
• delta – 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.
• rate = 1000 / [wave length + wave interlude] (Hz)

Repetitions

• number – number of repetitions (repN) of your stimulus protocol.
• interlude – time between repetitions (msec). Can be zero.
• rate = 1000 / [waveN * (wave length + wave interlude) + rep interlude] (Hz)