This module makes repetetive Ic(switching current) measurements at dc to kHz speed in combination with a current source module (e.g. S4m) and a voltage measurement module (e.g. M2b).
When a current sweep is made and the voltage across the sample [V-meas] passes a treshold value [Vref] it is assumed to be a switching action (switching or retrapping, positive or negative can be selected).
At that moment the value of the current source control voltage is sampled and hold and presented as a steady voltage [V(Ic)] at the output. So a [V(Ic)] of +1V means a switching current of +100% of the selected range of the used current source. Example: S4m on 100nA/V and a [V(Ic)] reading of 0.3V means a detected switching current of 30nA.
Each time an event is detected the [trig] LED flashes and an optical pulse is send via the [fibre-out] output. This [fibre-out] can be used to trigger the voltage-readout [V(Ic)] meter or just to count the switching event frequency. A fibre (1mm plastic core, grey coated) can be connected to a fibre-TTL-converter box (see picture below) That can trigger the commercial voltmeter (example: keithley 2000) to get 1 synchronised reading per switch event.
The treshold [Vref] can also be set remote (externally), when switched to [ext], by a DAC or Iso-amp (selected in the summing module).
The [mode] switch selects the type of event to trigger on.
