Optiview 4M - Manual (Page 9)

You pan/tilt automatically.(The button toggles between pan/tilt and stop)
Power on/off.
You can zoom in(+) or out(-).
You can focus in(+) or out(-).
You control the Iris.(Iris availability depends on pan/tilt protocol)
You control the Wiper.(Wiper availability depends on pan/tilt protocol)
You control the Light.(Light availability depends on pan/tilt protocol)
You return to display mode from pan/tilt control.
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