By Gary Armstrong
I have inherited a LabVIEW Interface that talks thru a USB2 Interface to a micro-Controller at 921,600 baud.
This opens a new world of possibilities as USB2 can handle data at much higher rates than a typical RS232 interface.
I have been tasked with rewriting the LabVIEW code as it is difficult to maintain. I have an application that will talk to the uC at 230 kbaud but can't attain the 921,600 baud. I have tried copying the pertinent VIs from the supplied code into my app but still can not attain 921,600 baud. Plus I don't have a serial line analyzer capable of handling USB2, so I can only trial and error with the uC. Is there a setting I have to do in LabVIEW to allow serial communications at the higher rates? At the moment, I am trying to get the Find Controllr VI to work. I have included the support VIs for the Find Controllr.vi. The Find Controllr VI attempts to find the correct port and baud rate and then obviously communicate with the uC.
Get Available Ports.vi
Check For Packet.vi
Extract Packet ID.vi
By Gan Uesli Starling
I have a LabVIEW program, which when operating with simulated input data is blazing fast during mock-up. As soon as I hooked into a real cDAQ on Windows, however, the update speed fell off to 4 seconds. That's awful slow. I don't really have a whole lot of channels. I have read tasks for Volts of maybe 5 channels, write tasks for both On./Off for maybe 10 channels (simultaneous) and write tasks for 4-20mA of only 5 channels. How may I improve on that? Is it maybe a priority issue in Windows or to do with USB? What? How to improve? Thanks in advance.
Hi, I have contacted NI sales services but it's a great frustration as usual, so I will try to get some support here
Basically for a project I need 2 CAN ports and I decided to go with XNET and Compact DAQ. I have 2 solutions I try to choose from:
Solution 1 --> One 4-slot chassis with 2 NI-9862 modules (one port per module)
Solution 2 --> One 1-slot chassis with 1 NI-9860 module (this module has 2 ports)
I am confident that solution 1 will work well since I already had a project in the past with one 4-slot chassis (cDAQ-9174) and one NI-9862 module. But going with solution 2 will allow me to cut cost significantly. I just want to make sure it will be absolutely seamless and transparent for the software. Does anybody have experience with the NI-9860? Can it be considered as the equivalent of 2x NI-9862 as far as the software is concerned (LabVIEW driver) or does it remove some performance/flexibility/other?
Lets pretend I wanted to simulate a solar panel using a cDAQ, a programmable power supply and a light sensor. Id have to measure the voltage from the light sensor and the PSUs current, use those values to find the respective operating point on my light/voltage/current-curve and update the PSUs settings. Lets also say I wanted to do this for multiple systems in parallel, all connected to 1 analog input and 1 analog output module in 1 cDAQ.
What would be the best way to achieve the quickest response time? Simply reading and writing single samples seams to be pretty slow (though I can encapsulate everything neatly this way).
Is there a better way?
I've been struggling with this problem for months now... I want to use a cDAQ9171+NI-9234 with an Advantech PC (AIMB-580). I have 3 computers like this and all with the same problem. I plug the USB cDAQ-9171, Windows detect the device and loads the proper driver (cDAQ-9171), it is displayed in MAX but self-test or reset always fails with error. At the same time, NI Devive Loader service hangs up. If I try to restart or stop this service it cannot complete the operation, the only way to finish this operation is to unplug the usb cable from the PC, then the service restarts correctly. Additionally the windows' event logger shows the next error message:
In one PC I re-installed Windows, installed DAQmx 14 and the problem was still there, this is with a Windows fresh-install... After this, I removed DAQmx 14 and installed DAQmx 9.8 (supplied in CD) and the it worked!!! I upgraded to DAQmx 9.9 and it was still working, so I stoped there as it was all I needed (9.8 has some bugs with NI-9234 that 9.9 solves).
One thing to note, when it works, Windows first install cDAQ-9171 driver, but then inmediatly it changes to USB flash firmware updater, after this it returns again to load cDAQ-9171 and detects the NI-9134. When it don't work it only installs the cDAQ-9171 and doesn't load anything more...
I tried in a second PC to repeat the process, but I have been not able to repeat the success, only the fail... I get the same error every time I plug the USB and I have not idea of what else try... I have disabled UAC, cleared the MAX data, reinstall windows 2 times, tried with DAQmx 9.8, 9.9 and 14. Forced USB flash firmware updater as Windows driver, changed BIOS settings (disable hyper-threading, VT extensions, USB legacy, etc.). I am almost sure that it is some kind of weird incompatibility or similar, the thing is that NI device loader always hangs-up. In the next days I'm going to try to copy the same exact configuration of BIOS from the working PC, just to be sure.