The SSI-4 Sensor Interface allows you to add 4 additional inputs to a Modular Tuning (MTS) log chain or function as a stand alone data logger with the included LogWorks software. The SSI-4 channel 1 is configured in defuault form for RPM however this can easily be customized for any external 0-5V sensor or frequency. Channels 2-4 are designed to measure frequency or duty cycle. Using the SSI-4 serial ports, users can daisy-chain other Innovate devices such as the LMA-3, DL-33 and TC-4. This complete kit includes program cable, patch cable, mounting hardware and software CD.Click Here for examples of how the SSI-4 and the Modular Tuning System can be daisy-chained to create a fully customized datalog interface.