Using the Optical Spectrum Analyzer
The Bandwidth/Sweep Menus
To select an external trigger
1Press the front-panel Bandwidth/Sweep key.
2Press the More BW/Sweep Functions.... softkey.
3Press the Trigger Mode.... softkey.
4Press the External softkey.
External triggering synchronizes the sweep with a signal connected to the rear-panel EXT TRIG IN connector. External triggering requires a TTL-com- patible signal with a minimum of 0 V and a maximum of +5 V. There is a time delay between the external trigger signal and the data measurement that is set by the Trigger Delay value.
To select the ADC trigger
1Press the front-panel Bandwidth/Sweep key.
2Press the More BW/Sweep Functions.... softkey.
3Press the Trigger Mode.... softkey.
4Press either the ADC+, ADC–, or ADC AC softkey.
The softkeys in the menu select the type of triggering for the analog-to-digital converter in the data acquisition hardware of the OSA. The ADC+ softkey trig- gers the OSA on the rising edge of the external trigger signal, and the ADC– softkey triggers it on the falling edge. The ADC AC softkey alternately triggers on the rising and falling edge of the external trigger signal. The amplitude measured on opposite edges are subtracted and the absolute value of the result becomes the trace amplitude value. The delay between the external trigger and the triggering of the analog-to-digital converter is set by the trigger delay value.