Encoder pulse edge counting on VBAI

[ekdms663]

Hi I am Dana and currently using smart camera 1772C.

I connected the incremental encoder (1200 pulses/revolution) to the camera in digital input port to trigger image acquisiton. 

This is working well and accurate when encoder is rotating at very slow speed.

But the problem is when it goes a little fast (1 revolution /sec). It cannot read edges because encoder pulses just remain at high (=1) and doesn't change at all.

On the monitor panel, I can adjust the sampling rate but the maximum is 150 Hz. Is this the reason why I cannot read the high speed pulses?

Please anybody help me !

Thank you

[dstrandb]

Hi Dana,

The sampling rate most likely maxes out at 150Hz because the digital lines can change that quickly, but I checked the specs for the 1772C, and it looks like the maximum frames per second for that specific smart camera is 65fps. In order to trigger off a 1.2kHz signal, you would have to divide the signal down to a maximum of 65Hz. 

[Brad]

When your viewing in the test panel it is using software polling to monitor the lines. The smart camera can actually use hw triggering to detect much faster changes so you should see the encoder count change with much faster signals. Read the specs to get the exact rate but its probably in the tens of kHz or more