Correlated analog and encoder readings with M-series

Question

Hardware: PCI-6220
Driver: NI-DAQmx
Software: VC++ 6.0
My goal is to collect synchronized (correlated) analog and encoder readings to provide position-based voltage and current information.
First question is regarding the potential alternatives and which is the best approach between these options:
1) A single task that reads required analog and counter information into the same buffer, seems easy to align the data using this approach.
2) A task to read analog data and a second task to read counter information, complicated by the need to reliably align the informatio from seperate buffers.
Next question is simple: can the PCI-6220 read 2 seperate encoders?
Hopefully, last question: where can I find documentation about where to connect A, B, and Z? So far all my searches have resulted in E series or 6602 counter examples and nothing on M series.
Thanks, Ed

Answer 1

Hi Ed,
To answer your questions:
>>First question is regarding the potential alternatives and which is the best approach between these options:
>>1) A single task that reads required analog and counter information into the same buffer, seems easy to >>align the data using this approach.
>>2) A task to read analog data and a second task to read counter information, complicated by the need to >>reliably align the informatio from seperate buffers
First of all, option one is not actually an option because you cannot have one task acquire two different types of data (eg analog and counter data). Therefore, option two is the way to go. It is not as hard as it seems. You can use Channel Z to trigger the analag input channels and once the analog and counter channels are triggered at the same time their data will automatically be aligned.
>>Next question is simple: can the PCI-6220 read 2 seperate encoders?
The PCI 6220 has two 32 bit counter channels, so it is possible to read two separate encouders. Here is a link to the product data sheet for this card: http://sine.ni.com/apps/we/nioc.vp?cid=14130⟨=US
>>Hopefully, last question: where can I find documentation about where to connect A, B, and Z? So far all my searches have resulted in E series or 6602 counter examples and nothing on M series.
You are right, it is difficult to find out where to connect channels A, B, and Z! The easiest to find this information is to create an NI-DAQmx counter Task in MAX (Measurement and Automation Explorer). Once you have followed all of the steps to create the task you will see the task information in the middle of the screen. There will be a settings tab and inside this tab it will tell you what pins to connect A, B and Z to. I went ahead and created tasks for ctr 0 and 1 in MAX to get the information on which pins to connect to A, B, and Z.
For ctr0: For ctr1:
A: PFI8 PFI3
B: PFI10 PFI11
Z: PFI9 PFI4
Please let me know if you have any further questions. Have a great day!
Jennifer