how to send a stop to a DAQcard from a pressure transducer

[dave2222]

legend,

thanks very much, my head was adduld.

thanks again

DAVE

[dave2222]

Hi Gerd,

I have a problem with the program u helped me with yesterday.  when i press run an error occurs. 

Error -200463 occurred at DAQmx Write (Digital 1D Bool 1Chan 1Samp).vi:1

Possible reason(s):

Specified read or write operation failed, because the number of lines in the data for a channel does not match number of lines in the data for a channel does not match the number of lines in the channel.

If you are using the Digital Waveform datatype, make sure the number of lines in the digital waveform matches the number of lines in the channel. If you are using boolean data, make sure the array dimension for lines in the data matches the number of lines in the channel.

Number of Lines in Channel: 8
Number of Lines in Data: 3

Task Name: _unnamedTask<1>

[MikeS81]

Hi dave,

the "task/channels in" control has no value in it.

Mike

[dave2222]

hi mike s81

im mike im not sure thats the problem as i have a task set up in it,  when i test the transducer in dMax it seems ok and have saved the tasks.  any other suggestions

Message Edited by dave2222 on 03-27-2008 07:39 AM

[MikeS81]

Hi dave,

i changed the red marked things. See the attached example.

Mike

[dave2222]

hi mike, thanks

the number of tasks and data are still different new error code though. 

Error -200524 occurred at DAQmx Write (Digital 1D Bool NChan 1Samp 1Line).vi:1

Number of Channels in Task: 1
Number of Channels in Data: 3

[MikeS81]

Hi dave,

if i select 3 channels in the "line" control and a task with only one analog input in the other control it works well.

Mike

[dave2222]

hi mike,

how are you.  I got that system working with your help. 

Just I am getting an error when I run the VI the system does not constantly update the pressure value comming in so this error occurs after a few cycles. 

I increased the number of times the data is read with no success.  can you suggest anything?

DAVE

Error -200279 occurred at DAQmx Read (Analog DBL 1Chan 1Samp).vi:1

Possible reason(s):

Attempted to read samples that are no longer available. The requested sample was previously available, but has since been overwritten.

Increasing the buffer size, reading the data more frequently, or specifying a fixed number of samples to read instead of reading all available samples might correct the problem.

Property: RelativeTo
Corresponding Value: Current Read Position

Property: Offset
Corresponding Value:

Task Name: MyVoltageTask0

[MikeS81]

Hi dave,

actually you use only 1000 samples. Either you change the sample mode to "Hardware Timed Single Point" or you stop the reading after you get your 1000 samples.

Mike

[dave2222]

hi mike,

thanks for the advice again, ive almost got this running now.  the sensor and motor are running.  only snag is when the pressure goes over the value at the "greater than" sign the system has an error.  This has the effect of stopping the program but the motor continues to run regardless. 

What seems to happen is when the pressure goes high the system goes from

Number of Channels in Task: 3
Number of Channels in Data: 3

to

Number of Channels in Task: 3
Number of Channels in Data: 8 which causes the failure

the error number is Error -200524 occurred at DAQmx Write (Digital 1D Bool NChan 1Samp 1Line).vi:1

Possible reason(s):

Write cannot be performed, because the number of channels in the data does not match the number of channels in the task.

When writing, supply data for all channels in the task. Alternatively, modify the task to contain the same number of channels as the data written