Resetting history on a waveform chart

[Tom Farrow]

Dear discussion forum,

My problem seems to have been answered a number of times on the discussion forum, but I cannot make any of the posted solutions work.

I have a very simple vi. to collect, graph and write to file some voltage measurements (actually skin conductance measures [as used in lie detection]).

I want the waveform chart to clear each time I run the script.

The posted solutions all suggest wiring an empty array to the history property node.

When I do this I get a broken wire, and an error about the type of dynamic data that I am trying to wire up.

I attach my vi. and would be grateful if someone could point out where I am going wrong.

Thanks in advance

Tom

[altenbach]

How about using an "invoke node" with method "Reinitialize to Defaults"?

(Also note that you should wire the error cluster to the loop to ensure that it happens before the loop starts.)

Message Edited by altenbach on 07-25-2005 09:26 AM

[johnsold]

Tom,

The Chart history property requires an array. (Pop up on the History node and Create Control. Then check the data type wired to it: an array of Dynamic Data Type. The Dynamic type is basically a cluster of numerics and an array.) To fix your history insert a Build Array function in the Dynamic Data Type wire or initialize an empty array with the Dynamic Data Type.

Lynn