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6.14 Sampling Trace Function
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FUNCTIONS
6.14 Sampling Trace Function
Note43
(1) Definition of Sampling Trace Function?
Note44
This function samples the device continuously on the High Performance model QCPU
at specified timings.
The sampling trace samples the contents of the specified device at a set interval
(sampling cycle), and stores the trace results at the sampling trace file.
(2) Applications of sampling trace
The changed contents of the device that program uses during debugging can be
checked at the specified timing.
The sampling trace function reads device contents if trigger conditions are satisfied.
(3) Sampling trace operation
The sampling trace file stores the trace setting and trace result necessary to perform
the sampling trace. When trace is started by using GX Developer, the trace is
performed as many times as specified.
The area for sampling trace is up to 60k bytes. (For the Universal model QCPU, there
is no restriction on capacity.)
The number of traces is a value divided by the number of bytes of the device where
the number of bytes of sampling trace area is set (N1+N2+N3 number of word
device points 2+(number of bit device points/16 2)
*1 *2
* 1 : Round up result of "number of bit device points/16" in the expression to the right of the decimal
point.
* 2 : The following values are added to the N1 to N3 corresponding to the items set in trace additional
information of trace condition settings screen.
N1 : Add "4" at setting time
N2 : Add "10" at setting step No.
N3 : Add "8" at setting program name
Note43
Note44
Figure 6.68 Sampling trace operation
The Basic model QCPU does not support the sampling trace function.
Basic
Basic
Note6.42
CPU module
Device
area
File
register
area
Specified
device data
3
Data for 1st time
Data for 2nd time
Data for 3rd time
Data for 4th time
Data for 5th time
Data for 6th time
Sampling trace area
n-1
n
Data for (n-1)th time
Data for n th time
When stored for n th time, the next
data overwrites the 1st time data.
Read to the
peripheral
device
Sampling trace area
1
2
3
4
5
6
n-1
n
GX Developer
Displays the
data for the
specified
amount
*3: If the trigger point is executed, the sampling trace area data is latched after sampling as many times as specified.
1
2
3
4
5
6
*
Sampling trace
data monitoring
Standard RAM/Memory card
