User`s guide

Operation Theory • 65
When the digital trigger condition of Card 1 occurs, Card 1 will internally
generate the ADCONV signal and output this ADCONV signal to
SSI_ADCONV signal of Card 2, 3 and 4 through the SSI/PXI connectors.
Thus we can achieve 16-channel acquisition simultaneously.
You could arbitrarily choose each of the 6 timing signals as the SSI master
from any one of the cards. The SSI master can output the internal timing
signals to the SSI slaves. With the SSI, users could achieve better
card-to-card synchronization.
Note that when power-up or reset, the DAQ timing signals are reset to use
the internal generated timing signals.