Spectrum Brands MC.31XX - Manual (Page 67)

Trigger modes and appendant registers Channel Trigger
(c) Spectrum GmbH 67
If you want to set up a four channel board to detect a triggerevent on either a positive edge on channel1 or a negative edge on channel3
you would have to set up your board as the following example shows.
Triggerlevel
All of the channel trigger modes listed above require at least one triggerlevel to be set (except TM_CHXOFF of course). Some like the window
trigger require even two levels (upper and lower level) to be set. Before explaining the different channel trigger modes, it is necessary to
explain the board’s series specific range of triggerlevels.
After the data has been sampled, the upper N data bits are compared with the N bits of the trigger levels. The amount of bits, the trigger
levels are represented with depends on the board’s series. The following table shows the level registers and the possible values they can be
set to for your specific board.
8 bit resolution for the trigger levels:
In the above table the values for the triggerlevels represent the digital values for the corresponding data width N of the triggerlevels. If for
example the triggerlevels are represented by 8 bit, the bipolar range would be -128 … 127. To archieve symmetric triggerlevels the most
negative value is not used and the so resulting range would be -127 … +127.
As the triggerlevels are compared to the digitized data, the triggerlevels depend on the channels input range. For every input range available
to your board there is a corresponding range of triggerlevels. On the different input ranges the possible stepsize for the triggerlevels differs
as well as the maximum and minimum values. The following table, gives you the absolute triggerlevels for your specific board’s series.
SpcSetParam (hDrv, SPC_TRIGGERMODE , TM_CHOR ); // Enable channel OR trigger mode
SpcSetParam (hDrv, SPC_TRIGGERMODE0, TM_CHXOFF); // Disable channel0 concerning trigger detection
SpcSetParam (hDrv, SPC_TRIGGERMODE1, TM_CHXPOS); // Set triggermode of channel1 to positive edge trigger
SpcSetParam (hDrv, SPC_TRIGGERMODE2, TM_CHXOFF); // Disable channel2 concerning trigger detection
SpcSetParam (hDrv, SPC_TRIGGERMODE3, TM_CHXNEG); // Set triggermode of channel3 to positive edge trigger
SpcSetParam (hDrv, SPC_TRIGGERMODE4, TM_CHXOFF ); // Disable channel4 concerning trigger detection
SpcSetParam (hDrv, SPC_TRIGGERMODE5, TM_CHXOFF ); // Disable channel5 concerning trigger detection
SpcSetParam (hDrv, SPC_TRIGGERMODE6, TM_CHXOFF ); // Disable channel6 concerning trigger detection
SpcSetParam (hDrv, SPC_TRIGGERMODE7, TM_CHXOFF ); // Disable channel7 concerning trigger detection
Register Value Direction Description Range
SPC_HIGHLEVEL0 42000 r/w Defines the upper level (triggerlevel) for channel 0 -127 to +127
SPC_HIGHLEVEL1 42001 r/w Defines the upper level (triggerlevel) for channel 1 -127 to +127
SPC_HIGHLEVEL2 42002 r/w Defines the upper level (triggerlevel) for channel 2 -127 to +127
SPC_HIGHLEVEL3 42003 r/w Defines the upper level (triggerlevel) for channel 3 -127 to +127
SPC_HIGHLEVEL4 42004 r/w Defines the upper level (triggerlevel) for channel 4 -127 to +127
SPC_HIGHLEVEL5 42005 r/w Defines the upper level (triggerlevel) for channel 5 -127 to +127
SPC_HIGHLEVEL6 42006 r/w Defines the upper level (triggerlevel) for channel 6 -127 to +127
SPC_HIGHLEVEL7 42007 r/w Defines the upper level (triggerlevel) for channel 7 -127 to +127
SPC_LOWLEVEL0 42100 r/w Defines the lower level (triggerlevel) for channel 0 -127 to +127
SPC_LOWLEVEL1 42101 r/w Defines the lower level (triggerlevel) for channel 1 -127 to +127
SPC_LOWLEVEL2 42102 r/w Defines the lower level (triggerlevel) for channel 2 -127 to +127
SPC_LOWLEVEL3 42103 r/w Defines the lower level (triggerlevel) for channel 3 -127 to +127
SPC_LOWLEVEL4 42104 r/w Defines the lower level (triggerlevel) for channel 4 -127 to +127
SPC_LOWLEVEL5 42105 r/w Defines the lower level (triggerlevel) for channel 5 -127 to +127
SPC_LOWLEVEL6 42106 r/w Defines the lower level (triggerlevel) for channel 6 -127 to +127
SPC_LOWLEVEL7 42107 r/w Defines the lower level (triggerlevel) for channel 7 -127 to +127