19
Pulse Width > 20ns
Pulse Width > 20ns
Rising edge trigger
event
Falling edge trigger
event
Figure 3-4: External Digital Trigger
SSI_AD_TRIG
The PCIe-69529 utilizes SSI Bus Number 5 to act as a System Synchronization Interface (SSI).
With the interconnected bus provided by SSI Bus, multiple modules are easily synched.
When configured as input the PCIe-69529 serves as a slave module and can accept trigger
signals from SSI Bus Number 5, asserted from other PCIe-69529 modules. When configured
as output, the PCIe-69529 serves as a master module and can output trigger signals to SSI
Bus Number 5.
Analog Trigger
The PCIe-69529 analog trigger circuitry can be configured to monitor one analog input
channel from which data is acquired. Selection of an analog input channel as the analog
trigger channel does not influence the input channel acquisition operation. The analog
trigger circuit generates an internal digital trigger signal based on the condition between
the analog signal and the defined trigger level.
Analog trigger conditions are as follows:
•
Positive-slope trigger: The trigger event occurs when the analog input signal changes
from a voltage lower than the specified trigger level to a voltage exceeding the
specified trigger level.
•
Negative-slope trigger: The trigger event occurs when the analog input signal
changes from a voltage exceeding the specified trigger level to a voltage lower than
the specified trigger level.
