7YY press and hold to activatesecondary function of a keyXX press and release to activateprimary function of a keyDual Function KeysPower keyProvides two functions:Press the key to turn the OPM4 on/off. The unit will turn off automatically five minutes•after the last key press.Press and hold the key to disable/enable the Auto Off feature.•Auto power down will occur after 5 minutes of inactivity.- to disable the Auto Off feature, press and hold the power key until “HELD P on”appears.- to enable the Auto Off feature, press and hold the power key until “HELD AOFF”appears.Wavelength/Backlight keyProvides two functions:Press and hold to toggle the Backlight on or off.•Press to cycle through the calibrated wavelengths• A .Note: When the OPM4 is receiving a wavelength ID’d light, it automatically switches tothe ID wavelengths. WAVE ID indicator B appears on the display.WAVE ID WAVE IDBBA AA-88.888888 nmμW-88.88 -88.888888 8888dB dBm dB dBmdB dBmnm nmμW μWSingle WAVE mode, orTri WAVE mode - second pageDual WAVE mode, orTri WAVE mode - first pagedB/dBm/μW keyProvides two functions:Press to toggle test readings between insertion loss in dB and power in dBm• A .Press and hold to view power in μW• B .WAVE IDAABB-88.888888 nmμWHz-88.888888dB dBmdB dBmnmμWOPM4 ModelsWdBdBm