Mode Gated Replay
Allowed trigger modes
(c) Spectrum GmbH
105
Negative TTL single edge trigger
This mode is for detecting the falling edges of an external TTL sig-
nal. The gate will start on falling edges that are detected after
starting the board.
As this mode is purely edge-triggered, the low level at the cards
start time, does not trigger the board.
With the next rising edge the gate will be stopped.
LOW TTL level trigger
This mode is for detecting the low levels of an external TTL signal.
The gate will start on low levels that are detected after starting the
board.
As this mode is purely level-triggered, the low level at the cards
start time, does trigger the board.
With the next high level the gate will be stopped.
Negative TTL double edge trigger
This mode is for detecting the falling edges of an external TTL sig-
nal. The gate will start on the first falling edge that is detected af-
ter starting the board.
As this mode is purely edge-triggered, the low level at the cards
start time, does not trigger the board.
The gate will stop on the second falling edge that is detected.
Register
Value
Direction
Description
SPC_TRIG_EXT0_MODE
40510
read/write
Sets the external trigger mode for the board
SPC_TM_NEG
2h
Sets the trigger mode for external TTL trigger to detect negative edges.
Register
Value
Direction
Description
SPC_TRIG_EXT0_MODE
40510
read/write
Sets the external trigger mode for the board
SPC_TM_LOW
10h
Sets the trigger mode for external TTL trigger to detect low levels.
Register
Value
Direction
Description
SPC_TRIG_EXT0_MODE
40510
read/write
Sets the external trigger mode for the board
SPC_TM_NEG |
SPC_TM_DOUBLEEDGE
08000002h
Sets the gate mode for external TTL trigger to start and stop on negative edges