Delta RMC151 - Manual (Page 188)

RMC70/150 and RMCTools User Manual
If you wish, you can use Dynamic Plot Upload registers 0-4 to do error checking,
as described below:
• Verify that the Samples Uploaded is the value you expect. It should be the
number of samples read per data set. If it is zero, you have read past the
end of the currently captured data and the data will be unusable.
You can make use of this to read a plot while it's capturing. You can
continuously make reads and only use the data when the Samples Uploaded
is not zero.
• Verify that the Current Index is the value you expect. It should be the index
of the first sample of the data returned in the read.
• Verify that the Plot ID is unchanged. If it has changed, it indicates that you
are no longer reading from the same plot. The plot has probably re-triggered
and is overwritten. Your data may be unusable.
Note:
If you attempt to read a plot with the Upload Mode set to 1, and the plot is
untriggered, the Upload Status will be set to 1 to indicate the error, and the
Current Index and Samples Uploaded registers will be 0.
d. Copy Plot Data to Buffer
Before the next read, you should, of course, copy the data you just read to a plot
buffer. The Samples Uploaded register reflects how many valid samples you read.
If you read past the end of the plot, the Samples Uploaded will be zero.
The data is returned in this format:
R
0
, R
1
, R
2
, R
3
,
R
4
A
0
,A
1
,A
2
... A
n-1
B
0
,B
1
,B
2
... B
n-1
C
0
,C
1
,C
2
... C
n-1
D
0
,D
1
,D
2
... D
n-
1
...
where
R
0
= Upload Mode/Status register
R
1
= Requested Read Samples register
R
2
= Current Index register
R
3
= Plot ID register
R
4
= Samples Uploaded register
A = sample from data set 0, B = sample from data set 1, etc.
n = number of samples read per data set.
Tip:
In order to use the plot data, you will probably need to know the sample period. The Sample
Period register contains that information.
Method 3: Read A Continuous Plot (Trending) - Continuous Data
Use this method to read plot data continuously. This method guarantees no gaps or
overlap of data, but it requires that the upload keeps up with the capture of data.
To use this method, the plot should be continuously capturing. To set the plot to
continuously capture, issue the Rearm Plot (103) command and do not trigger or start the
plot. Important: You must disable the plot's automatic trigger in the Plot Template
Editor.
This method uses the Dynamic Plot Upload Area registers.
To read a plot using this method, follow these steps:
1. Verify that the Plot is Continuously Capturing.
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