Counter synchronization problem on NI USB X 6343

[newbieeng]

Hi everyone,

I am trying to generate 2 ttl signal with a delay between each other. When I trigger the first counter, I want to get a second counter to start with a delay. I coded and attached it. Today, I realized that when I trigger the first counter, the second counter generates pulse immediately with the first one and then it generates a delayed one again. I think firstly they synchronize each other and then the second one generates the delayed signal. However, this way of working is not desired one for my experimental setup. How can I avoid this issue? I searched and saw arm start trigger option. Is it my solution? Could you help me on this please? Thanks in advance.

(Note: in the VI, I use two daq device, two frequency output channels on USB X 6353, the other two - problematic one - pulse time counter on USB X 6343)

(Addition: I measured today, the counter channel that I use USB X 6343 could not generate 5V signal, it is around 2.5V. Is there a way to get 5V TTL from counters? Because my camera trigger signal threshold value is higher than 2.5V, that's why I need 5V. By the way, all AOs of my device are employed, can't use them.)

[Kevin_Price]

Do you see the 2nd counter generate 2 distinct pulses for *every* pulse of the 1st counter?  I don't see any obvious reason for that in the code.

As to the 2.5V output, that's often a sign that the device you're attached to is a low impedance current sink that wants to draw more current than your counter can source. 

-Kevin P

[newbieeng]

Not for every pulse but the first run it generates 2 pulses. Today, I will test it again. I will let you know.

[newbieeng]

I tested the program an whole stuff. It was because of noise. When I reset all the staff and isolate, it works ok.

[MarkZheng]

Hi all,

I need DAQ expert help. Currently I encounter a issue on using multiple counter signals. There are only 4 counter signals to be used in DAQ USB 6343. If I require to use more than 4 counter signals by using this DAQ for my project, how do I connect more than 4 counter digital outputs for only 4 counter signals in the DAQ?

[Kevin_Price]

Not enough info to give a specific answer.  You should also probably start a new thread as your question doesn't sound closely related to the original topic.   I'd recommend putting it in one of the hardware-specific boards, but I can't tell which is most appropriate yet from among Counter/Timer, Multifunction IO, and Digital.

Please be sure to give a more complete description of what you are trying to do and what you perceive the limitations to be.

-Kevin P

[newbieeng]

Hello Mark,

You can use your analog outputs as a ttl signal generators. In the examples come with labview, there are a couple of analog signal generation examples. Take a look at the analog voltage generation with hardware timing. You can modify it to fit your purpose.