# Input Signal Requirements The SLG-20 is controlled by a pulse-width modulation (PWM) input signal. The pulse width ranges for valid input events are shown in the table below. | PWM | Input Event | | ----------------- | ----------- | | 800-1199us | DOWN | | 1200-1800us | NEUTRAL | | 1801-2300us | UP | | Other or No Input | FAILSAFE | If the input signal is not within a valid range, a **FAILSAFE** event will be triggered. If no input signal is detected for 500ms, a **FAILSAFE** event will be triggered. (This is configurable with the parameter FS\_MS) If a **FAILSAFE** event is triggered, the SLG-20 Legs will LOWERED. UP events will cause the legs to RAISE. DOWN events will cause the legs to LOWER. NEUTRAL events will have no effect. If the input signal is in the UP range on boot, the legs will not raise until the input is toggled to the DOWN range. This is a safety precaution for powering up the aircraft, in case the switch is in the wrong position. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://xm2labs.gitbook.io/slg20-retractable-landing-gear-altax-manual/operation/input-signal-requirements.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.