There are two versions of interrogators available, one called the Mini Trigger and the other is the Mini Analyser. Both are optional devices.
The Mini Trigger will transmit a message to a local sensor and force that sensor to transmit its data to the control box. Essentially turning on a stationary sensor for checking.
The more expensive Mini Analyser will request and monitor information directly from a sensor or group of sensors. It does not have to communicate through the control box. This is nice to check tires not mounted on the car and reports pressure, temperature, serial number and other bits of data.
Part # F1-100-1081-021 Basic Mini Trigger