ADLINK DAQe-2214 - Manual (Page 52)

40 Operation Theory
Middle-Trigger Acquisition
Use middle-trigger acquisition in applications where you want
to collect data before and after a trigger event. The number of
scans (M) stored before the trigger is specified in M_counter,
while the number of scans (N) after the trigger is specified in
PSC_counter.
Like pre-trigger mode, the number of stored data could be less
than the specified amount of data [NumChan_counter *(M+N)],
if an external trigger occurs before M scans of data are con-
verted. The M_enable bit in middle-trigger mode takes the
same effect as in pre-trigger mode. If M_enable is set to 1, the
trigger signal will be ignored until the first M scans of data are
converted, and it assures you with (M+N) scans of data under
middle-trigger mode. However, if M_enable is set to 0, the trig-
ger signal will be accepted at any time. Figure 4-6 shows the
acquisition timing with M_enable=1.
Figure 4-6: Middle-Trigger with M_enable = 1