Trigger modes and appendant registers
Channel Trigger
(c) Spectrum GmbH
101
Channel re-arm trigger on negative edge
The analog input is continuously sampled with the selected
sample rate. If the programmed re-arm level is crossed from
higher to lower values, the trigger engine is armed and
waiting for trigger. If the programmed trigger level is
crossed by the channel’s signal from higher values to lower
values (falling edge) then the triggerevent will be detected
and the trigger engine will be disarmed. A new trigger
event is only detected, if the trigger engine is armed again.
The re-arm trigger modes can be used to prevent the board
from triggering on wrong edges in noisy signals.
Channel pulsewidth trigger for long positive pulses
The analog input is continuously sampled with the selected
sample rate. If the programmed trigger level is crossed by
the channel’s signal from lower to higher values (rising
edge) the pulsewidth counter is started. If the signal crosses
the trigger level again in the opposite direction within the
the programmed pulsewidth time, no trigger will be detect-
ed. If the pulsewidth counter reaches the programmed
amount of samples, without the signal crossing the trigger
level in the opposite direction, the triggerevent will be de-
tected.
The pulsewidth trigger modes for long pulses can be used
to prevent the board from triggering on wrong (short) edges
in noisy signals.
Channel pulsewidth trigger for long negative pulses
The analog input is continuously sampled with the selected
sample rate. If the programmed trigger level is crossed by
the channel’s signal from higher to lower values (falling
edge) the pulsewidth counter is started. If the signal crosses
the trigger level again in the opposite direction within the
the programmed pulsewidth time, no trigger will be detect-
ed. If the pulsewidth counter reaches the programmed
amount of samples, without the signal crossing the trigger
level in the opposite direction, the triggerevent will be de-
tected.
The pulsewidth trigger modes for long pulses can be used
to prevent the board from triggering on wrong (short) edges
in noisy signals.
Register
Value
Direction
set to
Value
SPC_TRIG_CH0_MODE
40610
read/write
SPC_TM_NEG | SPC_TM_REARM
01000002h
SPC_TRIG_CH0_LEVEL0
42200
read/write
Defines the re-arm level relatively to the channels’s input range
board dependant
SPC_TRIG_CH0_LEVEL1
42300
read/write
Set it to the desired trigger level relatively to the channel’s input range.
board dependant
Register
Value
Direction
set to
Value
SPC_TRIG_CH0_MODE
40610
read/write
SPC_TM_POS | SPC_TM_PW_GREATER
04000001h
SPC_TRIG_CH0_LEVEL0
42200
read/write
Set it to the desired trigger level relatively to the channel’s input range.
board dependant
SPC_TRIG_CH0_PULSEWIDTH
44101
read/write
Sets the pulsewidth in samples. Values from 2 to 65535 are allowed.
2 to 65535
Register
Value
Direction
set to
Value
SPC_TRIG_CH0_MODE
40610
read/write
SPC_TM_NEG | SPC_TM_PW_GREATER
04000002h
SPC_TRIG_CH0_LEVEL0
42200
read/write
Set it to the desired trigger level relatively to the channel’s input range.
board dependant
SPC_TRIG_CH0_PULSEWIDTH
44101
read/write
Sets the pulsewidth in samples. Values from 2 to 65535 are allowed.
2 to 65535
