Spectrum M2p.59 Series, Руководство по оборудованию, Страница: 139 / 190

Mode Gated Sampling Trigger
(c) Spectrum Instrumentation GmbH 139
Low level trigger
The external input is continuously sampled with the selected
sample rate. If the signal is equal or lower than the pro -
grammed trigger level the gate starts.
When the signal is higher than the programmed trigger level
the gate will stop.
As this mode is level-triggered, the high level at the cards start
time does trigger the board.
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 gate will start.
If the programmed trigger level is crossed by the channel’s
signal from higher to lower values (falling edge) the gate
will stop.
The pulsewidth trigger modes for long pulses can be used to prevent the board from triggering on wrong (short) edges in noisy signals.
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 gate will start.
If the programmed trigger level is crossed by the channel’s
signal from lower to higher values (rising edge) the gate will
stop.
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_EXT0_MODE 40510 read/write SPC_TM_HIGH 00000008h
SPC_TRIG_EXT0_LEVEL0 42320 read/write Set it to the desired trigger level in mV. mV
Register Value Direction set to Value
SPC_TRIG_EXT0_MODE 40510 read/write SPC_TM_LOW 00000010h
SPC_TRIG_EXT0_LEVEL0 42320 read/write Set it to the desired trigger level in mV. mV
Register Value Direction set to Value
SPC_TRIG_EXT0_MODE 40510 read/write SPC_TM_POS | SPC_TM_PW_GREATER 04000001h
SPC_TRIG_EXT0_LEVEL0 42320 read/write Set it to the desired trigger level in mV. mV
SPC_TRIG_CH0_PULSEWIDTH 44101 read/write Sets the pulsewidth in samples. Values from 2 to [4G - 1] are allowed. 2 to [4G - 1]
Register Value Direction set to Value
SPC_TRIG_CH0_MODE 40610 read/write SPC_TM_NEG | SPC_TM_PW_GREATER 04000002h