ADLINK PCI-9846 - Manual (Page 45)

Operation Theory 35
3.4.2 External Digital Trigger
An external digital trigger occurs when a TTL rising edge or a fall-
ing edge is detected at the SMB connector TRG IO on the front
panel. As illustrated in Figure 3-8, the trigger polarity can be
selected by software. Note that the signal level of the external dig-
ital trigger signal should be TTL-compatible, and the minimum
pulse width is 20 ns.
Figure 3-8: External Digital Trigger Polarity and Pulse Width Requirement.
Rising edge
trigger event
Falling edge
trigger event
Pulse Width > 20 ns Pulse Width > 20 ns