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When using a "goose trigger", the laser (through the SDG) is fed a signal that is 10 Hz, but only a portion of that 10 Hz is used by the laser timing software. The "gate trigger" on the Keysight box tells the keysight box "start listening for a start and stop trigger". So in the diagram above the Keysight box is only updating at 9 Hz. The "bypass trigger" is a trigger that bypasses the laser timing system, so it can be changed to anything without disrupting the ability of the laser timing system to keep the laser and e-beam in sync.