Does NI 6704 Can Generate 400Hz Square?

[yiweihua2002]

Dear All:
      I have a PXI-6704 card,and I want to use this card to generate 400Hz Square waveform.I found a message from this card user manual like that:" The channels are sampled at a rate of 50 ?s per channel, meaning a channel can change value a maximum of 1.8 ms after it has been updated by software."
      And I want to ask:Does this card can generate 400Hz Square?If it can not,which frequence can it generate?

[yankaini]

Since 6704 is static AO board. which means you can update the value of AO voltage at the rate of AO loop execution. In Windows, the timing accuracy is about 1ms, and equals to 500Hz square wave when the duty cycle is 50%. However, this does not mean you can generate any squarewave that less than 500Hz, but rather, you can generate the frequency equals to 500 devided by an integer, such as 250Hz, 166Hz, 125Hz, and so on. If you want to generate squarewave, consider using counter when the voltage level is TTL.