error 89136 at DAQmx start task (Acq&Graph Voltage-Ext Clk-Analog Ref.vi)

[educob]

HI,

I am trying to run example vi Acq&Graph Voltage-Ext Clk-Analog Ref.vi ( I have made some modifcations) in labview 8.2

I am trying to read pressure (from a compressor),

I have an encoder with 1024 pulses per revolution,

So I want to read 1024 samples for each of the 1024 pulses of the encoder and use the encoder as the trigger (with a channel that gives one pulse per revolution),

I get the error above and I have no idea why (I don't understand the settings at all).

Please help.

[P@Anand]

You can see the reason for the error here

[educob]

Hi, 

thans for the answer.

I had already found that page but unfortunately I didn't understand it at all.

thanks

[nyc_(is_out_of_here)]

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@educob wrote:

Hi, 

thans for the answer.

I had already found that page but unfortunately I didn't understand it at all.

thanks

---

Are you saying that English is not your native language?

That linked page is VERY CLEAR that you are doing something you are not suppose to.

[educob]

Hi,

english is a foreigner language for me but i don't have significant problems understanding it.

My problem is lack of technical labview knowledge.

I want to read the pressure each time a encoder produces a pulse.

It  should be as easy as setting the trigger (the encoder signal for each complete revolution) and the external clock (the enconder train of pulses).

But as easy as it sounds I can't do it.

Thanks.

[nyc_(is_out_of_here)]

---

@educob wrote:

Hi,

english is a foreigner language for me but i don't have significant problems understanding it.

My problem is lack of technical labview knowledge.

I want to read the pressure each time a encoder produces a pulse.

It  should be as easy as setting the trigger (the encoder signal for each complete revolution) and the external clock (the enconder train of pulses).

But as easy as it sounds I can't do it.

Thanks.

---

Since that error message is telling that you are doing something that is wrong. I suggest you read the capabilities of the hardware. What you think the hardware should be able to do has no bearing on what it CAN do.

[Mcdan]

If you have the correct defaults saved with your VI, you have set a digital trigger source to APFI0, which is a terminal used only for importing analog signals for analog triggering.  If you are actually doing digital triggering, you'll need to use one of the regular PFI lines (which need to be fed with a signal which is TTL compatible).

Dan

[educob]

Thanks for the answer.

the card I am using is a pci 6221.

I know about the pfi ports and I am using them to connect the encoder (pfi0 for triger pfi1 for train of pulses).

The VI example had as a default APFI0 which I have no idea what it is.

Should I write pfi0 in that field?

Tomorrow I will try.

Thanks.

[Mcdan]

Yes, if your trigger signal is wired to PFI0, you'll need to update the 'Trigger Source' to reflect this.

Dan