Ocean Optics PC2000-PC_104 - Manual (Page 6)

PC2000-PC/104 Data Sheet
Strobe Signals
Single Strobe
The Single Strobe signal is a TTL HIGH pulse that occurs at the start of each integration period. This
pulse occurs 2 master clock cycles after the start of the integration period. The pulse is not generated
unless The Lamp Enable (S0) signal is set (Digital 1-TTL HIGH) in software.
Continuous Strobe
The Continuous Strobe signal is a pulse-train (50% duty cycle) whose frequency is determined by
software.
Synchronizing Strobe Events
For some applications it is necessary to view pulsed sources. If the application requires more than one
pulse per integration period, exercise care to insure a stable signal. The integration time must be set so
that an equal number of strobe events occurs during any given integration period. This synchronization
only occurs when the integration period is a multiple of a power of 2, since the strobe signal is the
master clock divided by a power of 2.
Triggering Modes
The PC2000-PC/104 supports four triggering modes, which are defined by the state of the software
controlled S0 and S1. Details of each triggering mode are discussed below.
Mode S1 S0
Normal 0 X
Software Trigger
0 X
Ext Synchronization 1 0
Ext Hardware Trigger 1 1
Normal (S1:S0 = 0:X)
In this mode, the PC2000-PC/104 uses the user-supplied integration clock (DB25: pin 23) and
continuously scans the CCD array.
External Software Trigger (S1:S0 = 0:X)
In this mode, the PC2000-PC/104 uses the normal integration clock. Since this mode is under software
control its functionality can be software defined. In this mode, Ocean Optics software, waits until the
Software Trigger Input (D3) line goes HIGH before it acquires an acquisition. The amount of delay
between the trigger pulse and when a spectrum is acquired is indeterminate because the delay is
dependent upon (1) how fast the software polls the D3 line and recognizes it is HIGH and (2) the
amount of time until the start of the next integration period. The integration time is under user control
in this mode. This mode must be implemented in the software that controls the data acquisition.
6 000-00000-000-05-0704