06-04-2013 07:43 PM
I am currently trying to log DC voltage readings from a AA battery to an ASCII file using LabVIEW SingalExpress 2009 and the USB-4065 DMM (digital multimeter). I have two steps:
1) Acquire Signal > DC Voltage using DMM
- set to 4.5 resolution with 3.333333E-5 sample period
2) Save to ASCII
- Set to append to file, I delete the file after every run
The fastest readings I can get is one data point written to the ASCII file every eighth of a second.
Additionally I am new to NI Software and LabVIEW, the LabVIEW SignalExpress software I have is only for Evaluation as it was included in the driver CD for the USB 4065 DMM.
Thank you in advance for any and all help!!! 😄
Solved! Go to Solution.
06-05-2013 06:21 PM
You are correct in assuming you need access to lower level functions in order to get those higher sample rates. In order to get those speeds we would need to disable a few parameters which are not made accessible through Signal Express. You can create a VI and then use a Call VI step in Signal Express to remain in the same environment.
06-06-2013 10:25 AM
You imply that you have LabVIEW, but are just new to it. I recommend using our DMM shipping examples, available in the NI example finder:
Go to the Help menu bar, then select Find Examples. Once the NI Example Finder opens, go to: Hardware Input and Output»Modular Instruments»NI-DMM»Multi-Point Measurements»Cont Acq & Chart Multiple Samples.vi.
With that VI open, decrease the resolution to increase the sample rate. If you're still not able to get as many samples per second as you'd like, I recommend reading the NI-DMM Help file (Start»All programs»National Instruments»NI-DMM»Documentation), particularly the 4065 measurement cycle (Devices»NI 4065»DMM Measurements»DMM Measurement Cycle) section. If you're still not able to measure as fast as you'd like, post up and we can look at other configuration/hardware options.