User manual

Operation Basics: Functional Overview
WFM 90 & WFM 91 User Manual
2–9
2 The EXT REF message appears in the Waveform and Vector display
modes when the video signal is locking to an external video
reference signal.
3 The sweep rate is only displayed in the Waveform display mode.
There is no sweep rate readout when 2 Field sweep is selected.
4 The MISSING SYNC message appears in all video display modes
when the signal reference has been lost.
5 The instrument software version number is displayed when the
Configuration menu is open with the
DISPLAY category selected.
6 The LOW BAT message is displayed when the instrument is battery
operated and the remaining battery power has reached a critically
low level. The remaining length of time that the instrument can be
operated reliably is dependent on the current operating mode.