Creating a virtual channel with correct timestamp

[spy_theod]

Hello to everyone,

When writing code I usually test it by simulating a slave device. In order to do so I need some variables with history points. But when I use a math routine to add values to a virual channel I see that the timestamp is not updated.

for example

While(1)
Minute=(Minute+1)
if (Minute==59) then
   delay(1)
   Minute=00
endif
v.meas.AddValue(v.meas.AddValue[0] * 100)
Delay(1)
endwhile

How will my virtual channel have the correct timestamp?

Thanks in advance.

[AzeoTech]

OK, first, since its real important and I get on everyone's case about it: watch your indentation.

Second, you don't really need to use addValue() with V. channels. Just do V.meas =

Third, you don't want v.meas.addvalue[0], you want v.meas[0]

Finally, the reason the time stamp isn't updating is because there is already a timestamp in the value you are trying to add to the channel. DAQFactory only puts a timestamp on a value when there isn't one available already. You can force a timestamp either by using .time or inserttime(). So either:

private x = v.meas[0] * 100

x.time = systime()

v.meas = x

or:

v.meas = inserttime(v.meas[0] * 100, systime(), 0)

Note that you can't do:

v.meas.time =

Once values are in channels, whether V or regular, you cannot edit them.

[spy_theod]

Thank you very much. It works fine. But what do you mean by this: "watch your indentation" ?

[AzeoTech]

You should indent whenever you have a block level command. This would include while(), if(), for(), try(), switch() and a few others. You indented correctly for the if(), but forgot to indent for the while() so I almost missed it when I first looked at the script.