minimum counts for 6602

[dh]

I'm using 6602 in both buffered event count and buffered period measure modes. I found one interesting thing. If there is no counts within one counting period, it gives "dataLossError". It means the source frequency must be bigger than the gate frequency so at least one count per period. If I choose source of 80MHz internal signal, the gate can go up to MHz without error. But if the gate is 1kHz and source has no signal, it gives "dataLossError" message.

[AlanArmstead]

In DAQmx, you can use a property node to change this functionality. There is a property node that allows you to enable or disable "Duplicate Count Prevention". To get a value written to the buffer when you get a rising edge on your gate and don't get a rising edge on your source, you need to make sure duplicate count prevention is enabled. It is a DAQmx Channel property node, select: Counter Input>>General Properties>>More>>Advanced>>Duplicate Count Prevention. There is some great information on this and other properties in the DAQmx Help. Usually (in Windows) the help is located at Start>>All Programs>>National Instruments>>NI-DAQ>>NI-DAQmx Help.
-Alan A.

[Kevin_Price]

Alan,

Is there a simple way to explain the choice of the terminology "Duplicate Count Prevention?" It seems so counter-intuitive to me -- when you enable prevention you can buffer more readings than when you disable it? Weird...

-Kevin P.

[AlanArmstead]

Kevin,
When I first saw that property, I thought the same thing. It does make a little more sense once you read the DAQmx documentation on that property. In the NI-DAQmx Help file, a search for "duplicate count prevention" will get you the documentation I am referring to. I don't think I can do a better job of explaining than that help file. None the less, it is still a little confusing.
-Alan A.

[amc50]

We are having similar problems. What is NI-DAQmx? We only have NI-DAQ Labview 6.1. We are having trouble finding information about "duplicate count prevention"? Could you be more explicit about where to find help for this. Thanks.

Alice.

[gus]

In Traditional NI-DAQ (which you are using), duplicate count prevention is referred to as "Synchronous Counting". You should enable this attribute.

gus....