VISA Read y=f(t) graph

[Trainee123]

Hello,

I am using VISA Read function to read motor current in string format from a motor controller. The string is read from the output "read buffer" of the VISA Read function. Is there a way to put the string value in a graph in function of time?

[GerdW]

Hi Trainee,

yes, there is: You need to parse the string to get the numeric values you're interested in!

For such questions it would be a great help to provide examples of these "strings" and their "string format"…

[Trainee123]

Thanks. The strings that I received are as follows : 

A=10

BA=15

When I looked at the return count indicator of VISA Read, it shows a value of 11. So I think there is a space after 10 and 15 of the above message.

Is there a way to extract just the number 10 and 15 and plot them in a two separate graphs in function of time? (Note : the values 10 and 15 are not constant, they change as time pass. The maximum digit of these two values are two digits; they can change from 0 to 99)

[Trainee123]

I think I made a mistake. It shouldn't be a space after 10 and 15 but rather an "enter" to jump to the next line. Can you help me please?

[GerdW · Accepted solution]

Hi Trainee,

something like this should do it:

[Trainee123]

Thanks again. I can't seem to find the chart function. May I know in which library it is located please?

[GerdW]

Hi Trainee,

I used ScanFromString, followed by Bundle (from Cluster palette)…

The terminal named "chart" is a chart on the front panel!

If you have problems recreating that simple snippet you should take the free online courses offered by NI on their website!

[Trainee123]

Sorry I just found it in the front panel library. There are chart and graph. May I know what is the difference? The graph looks better with the grid on. But I can't seem to wire the output to the graph.

[GerdW]

Hi Trainee,

LabVIEW comes with a lot of example VIs!

There are also examples explaining the difference of graphs and charts by illustrating how to use them…

[Trainee123]

I got an error message "LabVIEW: Scan failed. The input string does not contain data in the expected format" I attached a picture of the program. Can you help me please?