ScanImage 3.5 simplifies the scheme used to ensure that all data acquisition subsystems (each bank of Analog Input and Output channels per board comprises a subsystem) are synchronized.
- In ScanImage 3.5, all subsystems on a given board receive a trigger signal on a common digital input terminal. A TTL rising edge on this terminal causes each of the subsystems to begin recording or playback.
- ScanImage 3.5 allows the terminal used as a common input to be user-specified in the standard.INI file. Generally, the terminal is one of the 'programmable function interface' (PFI) terminals available on National Instruments boards.
ScanImage 3.0 required a separate trigger signal for each subsystem, as opposed to each board.
ScanImage 3.0 did not allow the terminal to be specified by the user. It required PFI0 be used by all the Analog Input subystem(s) and PFI6 for all the Analog Output subsystem(s).
The specified input terminal is generally (but not necessarily) connected to the trigger signal generated by ScanImage at the beginning of each acquisition. This trigger source is output on the digital output line specified by the triggerBoardIndex and triggerLineIndex values in the standard.INI file.
See Typical DAQ Board Wiring in Appendix 2 for drawings/photos of typical board connections
New Variables
triggerInputTerminal: Specifies the single Programmable Function Interface (PFI) terminal which the acquisition, mirror, and Pockels Cell board(s) will all use as their default trigger input. This terminal on the one or more boards is typically connected to the trigger source specified by triggerBoardIndex and triggerLineIndex.