Timing Pulse interval and width from WPI's Isostim are set with single-turn continuously variable controls from 5ms to 5.5s in three ranges. Pulse wdith is continuously variable from 50us to 500ms in four ranges.
Modes of Operation In FREE RUN, Isostim generates continuous square waves. In EXT?GATE or EXT SYNC modes, externally applied pulses can generate trains or single events. Single pulses or finite duration can be produced using a push-button on the instrument's front panel. EXT/DC mode converts Isostim to a passive stimulus isolator.
Dual Tone Audible Alarm A tone sounds when an open circuit is detected or when system compliance is reached. A second tone, which sounds when a signal is applied to the input, can only be heard if the batteries have sufficient charge to operate the isolator. A violation light advises when pulse width exceeds the interval.
Current Delivery Stimulus currents up to 10mA can be set on the front panel with a control knob and a two-position range switch. Output current is load-independent.
Power Isostim model A320D is powered by readily available 9-volt alkaline batteries (included). Under average use these will last several months before replacement is required.