Thanks for questions and answers! I collected everything into a new wiki page: http://wiki.elphel.com/index.php?title=FPSControl
Regards Sebastian On Wed, Feb 9, 2011 at 03:37, Andrey Filippov <and...@elphel.com> wrote: > Adam, > > this is the camera problem - seems like some old features (supported in > GUI) are broken in the later firmware, some new features are not controlled > from GUI. > > Sensor has 2 operation modes - free running and triggered. In the camera > you can set trigger to FPGA trigger generator (or you can trigger from the > external source, i.e. another camera). > The first (free running) mode can achieve higher frame rate and exposure > can overlap frames (while you are reading the current frame exposure of the > next one already began). In triggered mode the minimal frame period is the > frame readout time (same as the frame period in the free running mode) plus > exposure time plus 8 extra lines (some sensor internal overhead). > > On the other hand it is much easier to set any required frame period in > triggered mode than in free running - you can just specify the period in > single pixel clock increments (as long as it is above the minimal for this > image size and exposure, of course). In the free running mode the software > can only adjust frame period by changing vertical and horizontal blanking> > It is also possible to change the sensor clock frequency, but sensor "does > not like" when the clock is adjusted while it is running and may hang). > > This is why when you do not need the highest fps it is usually more > convenient to run sensor in triggered mode. It is not controlled by the > camera GUI, but you can change it from the custom script or with > parsedit.php. If you just open the > http://192.168.0.9/parsedit.php page it will show you some sample links to > control different parameters, just select the "External Trigger Controls". > You may even reduce the number of parameters using the following link: > > > http://192.168.0.9/parsedit.php?embed=0.1&title=External+trigger+controls&TRIG&TRIG_PERIOD > > Each parameter has a short description that would appear as a tooltip when > you put the mouse pointer over it. > > The triggered mode is turned on by setting TRIG=4, free running mode > TRIG=0. > > TRIG_PERIOD - frame period in pixel clock periods, by default the clock is > set to 96MHz. > > If you set something too long, camera may wait and wait... Refreshing the > page will not help, at some point all 3 currently specified instances of PHP > will be used (something did not work with dynamically increasing number of > instances) and you'll not be able to open any PHP-based pages (i.e. > parsedit.php). To recover from that condition (without power-cycling the > camera) you may telnet to the camera and run > killall -9 lighttpd # - that will kill web server and all PHP instances, > then restart them all. > > That PHP restart still will not "unfreeze" the camera from waiting the > trigger, the driver responsible for changing the run time parameters is > driven by the sensor frame sync interrupts, you may check the status of the > camera/sensor by refreshing the http://192.168.0.236:8081/pointers page - > it will work even when the main web server and php are busy. If frame > number is not changing - the sensor is not being triggered. In that case you > can open external trigger control page, set TRIG=0 and before applying > change the value in "Program ahead" column from 3 to 0 - in that case the > driver will not wait the frame sync interrupts before applying the > parameter(s). > > Andrey > > > > > _______________________________________________ > Support-list mailing list > Support-list@support.elphel.com > http://support.elphel.com/mailman/listinfo/support-list_support.elphel.com > >
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