The NeXus Trigger Interface
The NeXus trigger interface is a product we often suggest to our University and research clients as it is often important to have an accurate way of synchronising environmental events (sound, light or digital event) with data being captured with a NeXus 4, 10 or NeXus 32 system unit.
Whether your ultimate application is sport, physiology or clinical, the NeXus trigger interface can monitor different types of event simultaneously and use these to trigger the acquisition of physiological signals and mark the events in the captured data. The trigger interface monitors events with a sample rate of 2048 samples per second and the general precision is better than 1 millisecond.
The trigger interface supports the following types of stimuli or event:-
- Light sensor
- RS232 serial (this cannot be used simultaneously with the Light Sensor)
- Audio (line)
- On/Off switch
- Manual Switches (optional)
Notes on Usage
The light sensor is intended to syncronise an event on the PC monitor with the ExG/Aux signals of your NeXus device. In use, the light sensor can be taped to the corner of the PC monitor, for example. The sensor is plugged into the digital input of the Trigger Interface and in a VEP/ERP application it detects a black and white transition on the monitor. The area on the screen may be the size of the light sensor itself so the user is not distracted by the transition.
The microphone is intended to respond to sound events in the background environment. The sound level that activates the trigger is adjustable through the potentiometer located next to the microphone input. When a sound is generated above the set threshold, a trigger will be sent to the connected NeXus device and a marker is placed and labelled on the overview screen in BioTrace+ software.
The audio/line trigger arrangement is intended to connect to the audio/line output of a PC for example. If the PC generates a sound this generates a trigger on the Trigger Interface and produces a marker in the session overview screen for the NeXus device.
The whole package consists of the following parts
- NTI - The NeXus Trigger Interface unit
- NT-NB-CABLE - The output trigger cable for NeXus 16 and NeXus 32 devices
- NT-VIDEO - the light/video sensor
- NX-MIC - microphone
- K-AUDIO-2MS - audio line cable
- C-AUDIO-SPLIT - Audio jack plug splitter
- K-RS232-FM - Serial cable (RS-232)
- CC NTI - case for trigger interface and accessories