Multifunction DAQ
USB6008 - Included Software and Speed Problems
Hi RIchard,
1/ No instructions on how to use the included NI Logger software.
The application is designed to be a very simple setup so no documentation was made.
2/ Unable to work out how to get the NI Logger software to recieve 2 channels (seems to flick betwen them OK but can't select more than one - need 2 for my tests).
Type directly into the physical channel box, e.g. my device is Dev3 so for ai0 and ai1 I'd type
Dev3/ai0,Dev3/ai1
3/ Won't take in data (from 1 channel) at 1000 Hz or more (currently trying to clean computer to increase speed which may fix this). Does samples per channel affect this?
Do you have anything else on the USB ports? Samples per channel does not affect this directly, but if you set it to say 50 then your chart will update at samples per channel / sample rate, i.e. setting both to 50 will update the chart once per second, with 50 points in one go, acquired at the specified rate. This means screen updates are less frequent, freeing up the computer to do the acquisition.
4/ Cursors (0 and 1) do not display the co-ordinate value in the X axis after you have moved them (bug in program). I need this function to work to measure the time span from the graph.
Yes they do update, however, the number is not a "time" value as you could read it, but the number of seconds since Jan 1st 1904. As such it's rather large (3000000000 ish) and the box isn't wide enough to display the small changes.
I agree this is going to stop you taking direct measurements from the graph, however you will have all the data as an excel spreadsheet so you can do post analysis on this instead. The other option is to program the features you require yourself in labview, or another programming language.
5/ Can you only plot using plot 0. What about 1, 2 and 3.
This is automatic based on the number of physical channels specified i.e. Dev3/ai0,Dev3/ai1,Dev3/ai2,Dev3/ai3 would use all 4 plots
6/ What does changing the chart history do?
This is the amount of data you can see in one go on screen. Try setting the sample rate to 50, and the history to 200. Run it and in about 4 seconds it will start to scroll across the screen.
7/ Can you change the x scale to read time from 0 (without date and time info).
The formatting and precision of the chart is fixed, so time information is always included
8/ What does samples per channel do? (sound obvious but!!. Does it average).
It doesn't average. THe acquisition is set off, and then the software retrieves that data from memory. The samples per channel says how many to read at once. (See answer 3)
Hope this helps
Sacha Emery
National Instruments (UK)
1/ No instructions on how to use the included NI Logger software.
The application is designed to be a very simple setup so no documentation was made.
2/ Unable to work out how to get the NI Logger software to recieve 2 channels (seems to flick betwen them OK but can't select more than one - need 2 for my tests).
Type directly into the physical channel box, e.g. my device is Dev3 so for ai0 and ai1 I'd type
Dev3/ai0,Dev3/ai1
3/ Won't take in data (from 1 channel) at 1000 Hz or more (currently trying to clean computer to increase speed which may fix this). Does samples per channel affect this?
Do you have anything else on the USB ports? Samples per channel does not affect this directly, but if you set it to say 50 then your chart will update at samples per channel / sample rate, i.e. setting both to 50 will update the chart once per second, with 50 points in one go, acquired at the specified rate. This means screen updates are less frequent, freeing up the computer to do the acquisition.
4/ Cursors (0 and 1) do not display the co-ordinate value in the X axis after you have moved them (bug in program). I need this function to work to measure the time span from the graph.
Yes they do update, however, the number is not a "time" value as you could read it, but the number of seconds since Jan 1st 1904. As such it's rather large (3000000000 ish) and the box isn't wide enough to display the small changes.
I agree this is going to stop you taking direct measurements from the graph, however you will have all the data as an excel spreadsheet so you can do post analysis on this instead. The other option is to program the features you require yourself in labview, or another programming language.
5/ Can you only plot using plot 0. What about 1, 2 and 3.
This is automatic based on the number of physical channels specified i.e. Dev3/ai0,Dev3/ai1,Dev3/ai2,Dev3/ai3 would use all 4 plots
6/ What does changing the chart history do?
This is the amount of data you can see in one go on screen. Try setting the sample rate to 50, and the history to 200. Run it and in about 4 seconds it will start to scroll across the screen.
7/ Can you change the x scale to read time from 0 (without date and time info).
The formatting and precision of the chart is fixed, so time information is always included
8/ What does samples per channel do? (sound obvious but!!. Does it average).
It doesn't average. THe acquisition is set off, and then the software retrieves that data from memory. The samples per channel says how many to read at once. (See answer 3)
Hope this helps
Sacha Emery
National Instruments (UK)
Sorry, forgot to mention,
the maximum analog input rate for the 6008 is 10000 S/s, but you then have to divide this down by the number of channels used, i.e. for two channels, you can only specify 5000 S/s in the Sample rate box, since this is actually the rate it will keep coming back to the same channel in a "scan list", i.e. total sample rate is still 10000 if you sepcify 5000 in the box, but it's split across the channels since it's doing ai0, ai1, ai0, ai1, ai0, ai1, ai0, ai1, ai0, ai1 etc
Thanks
Sacha Emery
National Instruments (UK)
the maximum analog input rate for the 6008 is 10000 S/s, but you then have to divide this down by the number of channels used, i.e. for two channels, you can only specify 5000 S/s in the Sample rate box, since this is actually the rate it will keep coming back to the same channel in a "scan list", i.e. total sample rate is still 10000 if you sepcify 5000 in the box, but it's split across the channels since it's doing ai0, ai1, ai0, ai1, ai0, ai1, ai0, ai1, ai0, ai1 etc
Thanks
Sacha Emery
National Instruments (UK)
