Princeton 4300 User Manual

58 

PI-SCX System Manual 

Version 2.E 

 

58 

Note: If EXT SYNC is still active (in Figure 25, this means that if it is still LOW) at the 

end of the readout, the hardware may interpret this as a second sync pulse, and so on.  

 

Another timing mode available with the ST-133 controller is called Continuous Cleans. 

In addition to the standard "cleaning" of the array, which occurs after the controller is 

enabled, Continuous Cleans will remove any charge from the array until the moment the 

External Sync pulse trigger edge is received.  

 

Once the External Sync pulse trigger edge is received, cleaning of the array stops as soon 

as the current row is shifted, and frame collection begins: a delay time of up to one row 

shift can be expected. With Normal Shutter operation the shutter is opened for the set 

exposure time. With PreOpen Shutter operation the shutter is open during the continuous 

cleaning, and once the External Sync pulse trigger edge is received, the shutter remains 

open for the set exposure time, then closes. If the vertical rows are shifted midway when 

the External Sync pulse trigger edge arrives, the pulse is saved until the row shifting is