Calculation of input data & storage to VChannel

[asaikk]

What would be the procedure and sequence to process below 1) & 2)

1)Calculate the hourly average of input data from "MyChannel"

2)Store the average data in the VChannel named "MyVChannel"

Thanks in advance

[AzeoTech]

Its actually similar to your recent inquiry concerning hourly logging files and a technique used in a number of similar inquiries on this forum when you want to do something on the hour, day, week, etc. But first, I'd recommend using a Test channel instead of a V channel. Make it device type "Test", A to D, Timing = 0. Call it MyChannelAverage for this exercise. The script would be:

if (formatDateTime("%H", myChannel.time[0])  != formatDateTime("%H", myChannel.time[1]))
   private endtime = myChannel.time[1]
   private starttime = endtime - (endtime % 3600)
   private themean = mean(myChannel[starttime, endtime]
   themean.time = endtime
   myChannelAverage.addValue(themean)
endif

This should go in the Event for myChannel, not in a sequence.

[asaikk]

Thank you for the advice.

However the program installed with the event (which I attach on this reply) does not work.

I would appreciate if you would check it.

Thanks in advance.

test_HourlyLog_Average.ctl

[asaikk]

Please replace the attached file with this one, as the former one may not reflect all the change I made, though this one does not work either.

test_HourlyLog_Average.ctl

[AzeoTech]

I'm sorry. I seem to be off this week, putting all sorts of typos in the forum script. Anyhow, you can't have a variable called "mean" because its a reserved word for the function mean() that we actually use. Anyhow, I've corrected the post above.

[asaikk]

Concerning the sequence above, would you teach me the two questions below?

1)When executing the sequence, I think new channel "myChannelAverage" should be created.

If it is right, then how the items (I/O Type, Chn #, Timing, etc) of the "myChannelAverage" should be set?

2)Does this sequence calculate the hourly mean every minute?

Thanks in advance

[AzeoTech]

1) No, you have to create MyChannelAverage yourself in the Channel Table.

2) No, it calculates it once an hour.

[asaikk]

Thank you for the reply.

When creating MyChannelAverage in the Channel Table, what values should I input for the items (I/O Type, Chn #, Timing, etc)?

[AzeoTech]

Device Type: Test

I/O type: A to D

D# : 0

Chan #: something unique to your other Test channels

Timing: 0

rest, whatever you want.

[asaikk]

Many thanks for the advice.

I succeeded in making the program run.

PS

I corrected the command you wrote ;

myChannelAverage.addValue(mean)

to

myChannelAverage.addValue(themean)

[asaikk]

Would you give me the explanation of the meaning of the line below, which is in the parentheses of the "if" sentence?

formatDateTime("%H", myChannel.time[0]) != formatDateTime("%H", myChannel.time[1])

especilly,

!=

Thank you in advance.

[AzeoTech]

!= is the not equals operator. Its the same as C and JavaScript and Java and a number of other languages. Please review section 4.12 of the user's guide for all the operators and functions.

The expression itself is simply looking at the current hour of the most recent data point and comparing it to the hour of the second most recent data point. If they are not equal, then the hour has turned over.