PID in LabVIEW

[GerdW · Accepted solution]

Hi Milon,

see this one…

[Chowdhury_Milon]

hello Mr. GerdW

1. Thanks for your patient and continuous support. Would you check the attached error picture, please? How can I add 2 or 3 physical channel in DAQmx? I am using NI USB 6009 in the device setup.

2. During the use of DAQ Assistant, everything is ok but the graph only displays 1 line (for 1 setpoint). why doesn't it show 2 setpoint lines? 

Thanks in advance. 

[GerdW]

Hi Milon,

1. You need to select more than one channel in the "physical channels" DAQmx channel selector. Read the help to learn how to do this! Did you read the explanation of the error? (Read the help to learn how to do that, too!) You forgot to wire the PID correctly…

2. Your DAQAssistent is configured to read just one channel so it gives you samples for this one channel. Why do you expect more data than you have it configured for?

Do you know this one?

[Chowdhury_Milon]

Hello Mr. GerdW

1.I have fixed the error -200525 but 1 new error -200459 has appeared. I can't fix it. The error said to connect channels with "DAQmx write". how can I do that in that condition? Would you give me some hints/suggestion, please?

2. Setpoint and graph problem has been fixed also. I want to save the data for future use. I have added a saving option but the problem is 2 data (for 2 setpoints) are saving together. it will be very difficult to separate them. How can I manage the code to save them separately? (Picture attached)

Thanks in advance. 

[GerdW]

Hi Milon,

1. So you created a DAQmx task with some AI (analog INPUT) channels - and wonder why you cannot use them for AO (analog OUTPUT)??? Really? Even after reading the error message???

LabVIEW comes with a huge library of example VIs, there are also example VIs showing how to use AI with a PID to generate an AO value!!!

2. Here the same: look at some examples showing you how to save data to (spreadsheet) files…

[Chowdhury_Milon]

Hi GerdW,

I was searching some previous post in LabVIEW and found one related to my problem. I followed the instruction but I can't find out the data file on my computer. What is the problem? VI File attached.