APPEND A NEW CHANNEL TO AN EXISTING TASK

[El_Tipo]

Dear all,

On my application, i create a new task (say pressure) and initially it will have 1 channel (say 0-3000 PSI) representing the pressure transducer.

Now, on a later time I might need to add a new pressure transducer to my application and therefore a new channel (say 0-100 PSI)

after adding this new channel i should have one task (pressure) with two channels (0-3000 psi) and (0-100 psi).

i have tried several approachs such as (create a new channel vi), but if i look inside the max the iam unable to see the new appended channel.

mind i want to a some point be able to open max and calibrate those channels.

any help will be greatly appreciated.

[AdnanZ]

Are you creating this new channel in LabVIEW and then adding it to task that already exists with one channel in MAX? Then you won't be able to 'see' the new channel as part of the task in MAX. If you want both channels to exist in the task in MAX, then you will have to create the channel as part of the task in MAX itself. Please do let me know if i haven't understood this correctly.

[El_Tipo]

---

@adnan Z wrote:

Are you creating this new channel in LabVIEW and then adding it to task that already exists with one channel in MAX? Then you won't be able to 'see' the new channel as part of the task in MAX. If you want both channels to exist in the task in MAX, then you will have to create the channel as part of the task in MAX itself. Please do let me know if i haven't understood this correctly.

---

thanks for the replay Adnan,

you indeed underestood me correctly.

I woud like to create a new channel(programatically) in labview and then add it to a task that already exists (with one(or more) channel(s) in it already), and be able to open it in max at a later time for calibration purposes.

the reason i was thinking of doing it this way is because i do not know what parameters(range/output) the new sensor i will be adding to my application will have.

It will be updated depending on the need.

now what i tried while i was WAITING for answers on the forum, was instead of adding the new transducer-channel(say 0-1000 PSI) to the already created task(say PRESSURE); I created a new daqmx task and i called it (0-1000 PSI).

Since i need to do an xy-chart recorder with any two tranducer [ i have encounterd the problem of "the specified resources is reserved" do to the fact that i have tried to use two different tasks under the same HW card.

I learned that one way to erradicate this error was by clearing the first task before aquiring from the second task. (on the while loop where iam aquiring I decided to aquire 1 sample per channel, always clearing the 1st task before the 2nd starts, use the buildxy.vi and wire it to my xy graph. The only problem i have with this approach is the fact that i cant alter the sampling frequency, so when i compared with an aquivalent vi (in this case using the daqmx assistant to create both express task) variant#2, i found that it was smoother than variant#1 snce i increased the sampling rate to up to 5 times the sample#.

can the shapiness of the adquisicion be improved? note: i have selected on my xy smooth updates

any suggestion or variants on how accomplish this will be greatly appreaciated.

[AdnanZ]

Well, one way to avoid this is to use the channels in the same task and then just look at the data that you are interested in. Also, not to plug, but we have a XY Plotter software that we sell that might make your life easier:

XY Plotter - Austin Consultants

[El_Tipo]

---

@adnan Z wrote:

Well, one way to avoid this is to use the channels in the same task and then just look at the data that you are interested in. Also, not to plug, but we have a XY Plotter software that we sell that might make your life easier:

---

that is indeed one solution, but i believe i would have to add all the possible type og transdcucers(channels) to my task(PRESSURE), and unfortunatly i would need hundreds of different possible transducers(channels) that would defeat the purpose in my opinion. is there any other available way of acomplishing this?

thanks in advance