NF DP420LS Instruction Manual page 192

4.19 Synchronizing the Output Frequency with the Power Line or the External Signal
 Operation procedure
1. If you want to synchronize the internal signal source with the external signal, input the
synchronization signal by using the external signal input connector. If you want to synchronize
it with the power line, this step is not necessary.
2. Press the [Osc] soft-key and select [3:SYNC] from [2:Source].
3. In the [Source] item, select [Line] (power input) or [Ext] (external input signal) as the
synchronization signal source.
4. When the internal signal source is synchronized with the external signal or the power line, the
icon is displayed.
DP420LS/DP480LS
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