Spectrum Brands MC.31XX - Manual (Page 65)

Trigger modes and appendant registers External TTL trigger
(c) Spectrum GmbH 65
TTL pulsewidth trigger for long LOW pulses
This mode is for detecting LOW pulses of an external TTL signal
that are longer than a programmed pulsewidth. If the pulse is
shorter than the programmed pulsewidth, no trigger will be de-
tected. The board will trigger on the first pulse matching the trig-
ger condition after starting the board. The next triggerevent will
then be detected, if the actual recording/replay has finished and
the board is armed and waiting for a trigger again.
TTL pulsewidth trigger for short LOW pulses
This mode is for detecting LOW pulses of an external TTL signal
that are shorter than a programmed pulsewidth. If the pulse is
longer than the programmed pulsewidth, no trigger will be detect-
ed. The board will trigger on the first pulse matching the trigger
condition after starting the board. The next triggerevent will then
be detected, if the actual recording/replay has finished and the
board is armed and waiting for a trigger again.
Register Value Direction Description
SPC_PULSEWIDTH 44000 r/w Sets the pulsewidth in samples. Values from 2 to 255 are allowed.
SPC_TRIGGERMODE 40000 r/w Sets the triggermode for the board.
TM_TTLLOW_LP 20011 Sets the trigger mode for external TTL trigger to detect LOW pulses that are longer than a programmed pulsewidth.
Register Value Direction Description
SPC_PULSEWIDTH 44000 r/w Sets the pulsewidth in samples. Values from 2 to 255 are allowed.
SPC_TRIGGERMODE 40000 r/w Sets the triggermode for the board.
TM_TTLLOW_SP 20012 Sets the trigger mode for external TTL trigger to detect LOW pulses that are shorter than a programmed pulsewidth.
SpcSetParam (hDrv, SPC_TRIGGERMODE, TM_TTLHIGH_LP); // Setting up external TTL trigger to detect high pulses
SpcSetParam (hDrv, SPC_PULSEWIDTH , 50 ); // that are longer than 50 samples.