Acqiris SA240P - Trigger

1.5 Trigger
Acqiris SA240P User's Manual 15
1.5 Trigger
The trigger settings applied to the ADC card are used to determine at which time the device will start
recording data. The various trigger settings are outlined below.
Trigger source
The trigger source can be:
the signal applied to an input channel (internal triggering)
an external signal applied to the TRG IN front panel input connector (external triggering)
a self-trigger (See Self-Trigger (page 57) for this specific mode)
a software trigger (See How to generate a software trigger? (page 76)).
The different trigger modes are detailed in section Trigger modes and time-stamps (page 54)
Trigger impedance & coupling
The SA240P has a fixed 50 Ω termination impedance with DC coupling.
Trigger input bandwidths
The bandwidth depends on the trigger source.
Channel trigger
The -3 dB bandwidth of the comparator of the channel triggers is from DC to 2.5 GHz.
External trigger
The external trigger input has a bandwidth from DC to 3 GHz.
Refer to section How to set the external trigger? (page 78) for additional information.
Trigger level
The trigger level specifies the voltage at which the selected trigger source will produce a valid
trigger. All trigger circuits have sensitivity levels that must be exceeded in order for reliable trigger to
occur.
Both the external trigger input and channel triggers have a hysteresis of 1% of FSR (Full Scale
Range).
On the external trigger, the Full Scale Range FSR is ±5 V, therefore the ADC card will trigger on
signals with a peak-to-peak amplitude > 0.5 V.
When using the channel triggers, the trigger level must be set within Offset ± FSR .