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NI 1483R TTL/Digital I/O



i need help on how to change the Trigger/Digital Input polarity for NI 1483R Camera Link Adapter from "active high" to "active low".

when i read the manual, they state that this POLARITY is programmable (see picture below).


Trigger Manual.PNG


i do my FPGA program and its shows the Trigger/Digital input is active high. can somebody help me to change to active low?

i disable all Trigger/TTL/Digital Output (see picture below)


Test IO.png

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I don't believe that there is any built-in triggering functionality in the 1483, and rather any triggering that goes on must be programmed in your LabVIEW VI. I suspect that this is what they mean by "programmable polarity." Since you just read/write to the four TTL lines directly, you can adapt your VI to interpret high or low on those lines as "active" however you see fit.


The FVAL, LVAL, and DVAL active high settings correspond to frame/line/data valid signals, which are part of the camera link interface. The settings on those can be set using an FPGA I/O node in your VI and should match the settings of your camera.

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Hi etgohomeok,

thank you for the reply..


i used a multi meter to prove. without any fpga running, I just disconnect all connections and measure the IO port using multi meter. they still give me active high (5V).


please advise. 

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