The trigger command causes the board to change its state to the Run state and can be originated from the following sources:
● Software (PC)
● External trigger control line
● External event lines (16 lines)
● PXI Trigger Bus Line.
The software trigger originates within the PC. The PC bus trigger command takes effect immediately and overrides other established trigger conditions.
External triggers originate from the external trigger line. A low level signal causes the board to change its state to RUN. The external trigger line overrides other trigger conditions set for the GX5295 board.
It is also possible to set a conditional trigger command, which is activated upon receiving external events from these input lines. The external event may be any expected value on all or part of the external event input lines. The 8 external event lines are ANDed with pre-defined masks and compared with pre-defined events in registers D and T.
The external events trigger function is shown in the figure below:
External Events Trigger Block Diagram
The external events trigger can be set to one or two levels. In the one level mode, the trigger will be generated after the external condition has been met with the D or T event mask registers. In the two level mode, the board will wait for two sequential events to be met before issuing the trigger signal (D first, T second or opposite).
Controlled by software, the GX5295 can be programmed to trigger on any one of the PXI Trigger Bus Lines. The selected PXI Trigger Bus Line can then be Enabled/Disabled through software control achieving additional control over the PXI Trigger Bus event.