Spectrum Brands MI.61XX 用户手册

58

MI.61xx Manual

General Description

Trigger modes and appendant registers

Concerning the trigger modes of the Spectrum MI, MC and MX D/A boards, you can choose between three external TTL trigger modes and 
one internal software trigger. This chapter is about to explain the different trigger modes and setting up the board’s registers for the desired 
mode. Every analog Spectrum board has one dedicated SMB connector mounted in it’s bracket for feeding in an external trigger signal or 
outputting a trigger signal of an internal trigger event. As only one connector is available for external trigger I/O, it is not possible to forward 
the external trigger signal that is fed in to another board. If this is necessary, you need to first split up the external trigger signal.

The software trigger is the easiest way of triggering any Spectrum 
board. The acquisition or replay of data will start immediately af-
ter starting the board. The only delay results from the time the 
board needs for its setup.

In addition to the softwaretrigger (free run) it is also possible to force a triggerevent by software while the board is waiting for an internal or 
external trigger event. Therefore you can use the board command shown in the following table.

Due to the fact that the software trigger is an internal trigger mode, you can optionally enable the external trigger output to generate a high 
active trigger signal, which indicates when the data acquisition or replay begins. This can be useful to synchronize external equipment with 
your Spectrum board.

Example for setting up the software trigger: 

Enabling the external trigger input is performed by one of the following external trigger modes. The dedicated register for that operation is 
shown below.

If you choose an external trigger mode  the SPC_TRIGGEROUT register will be overwritten and the trigger connector will be used as an input 
by default.

SPC_TRIGGERMODE

40000

r/w

Sets the triggermode for the board.

TM_SOFTWARE

0

Sets the trigger mode to software, so that the recording/replay starts immediately.

SPC_COMMAND

0

r/w

Command register of the board.

SPC_FORCETRIGGER

16

Forces a trigger event if the hardware is still waiting for a trigger event. Needs a base board hardware version > 7.x.

SPC_TRIGGEROUT

40100

r/w

Defines the data direction of the external trigger connector.

0

The trigger connector is not used and the line driver is disabled.

1

The trigger connector is used as an output that indicates a detected internal trigger event.

SpcSetParam (hDrv, SPC_TRIGGERMODE, TM_SOFTWARE); // Internal software trigger mode is used
SpcSetParam (hDrv, SPC_TRIGGEROUT , 1          ); // And the trigger output is enabled

SPC_TRIGGERMODE

40000

r/w

TM_TTLPOS

20000

Sets the trigger mode for external TTL trigger to detect positive edges.

TM_TTLNEG

20010

Sets the trigger mode for external TTL trigger to detect negative edges

TM_TTLBOTH

20030

Sets the trigger mode for external TTL trigger to detect positive and negative edges

SPC_TRIGGEROUT

40100

r/w

Defines the data direction of the external trigger connector.

X

If external triggermodes are used, this register will have no effect.