Yokogawa PC-Based MX100 - Manual (Page 6)

IM MX190-02E
6
Retrieving Data with the API or Extended API
The following describes retrieving measured data from a FIFO buffer using the API or
extended API.
Program Flow
The flow of programs that retrieve the MX100's measured data are shown respectively
for the API and extended API in the tables below. Please refer to the program examples.
See the appendix for the locations of the program examples.
API Function Program Flow
Retrieval of
measured
data
1 Start FIFO
2 Get the retrievable data range from the FIFO buffer
3 Get the measured data time information from the FIFO buffer
4 Get the measured data values from the FIFO buffer
5 Stop FIFO
You can retrieve measured data from a FIFO buffer continually
by repeating 2, 3, and 4.
Extended
API
Function Program Flow
Retrieval of
measured
data
1 Start FIFO
2 Advance one measurement point
3 Retrieve the measured data at the measurement point
4 Stop FIFO
The program advances by one measurement point each time
2 is executed. Thus, you can retrieve measured data in order
by repeating 2 and 3.
With the API
The figure below shows the conditions when the API retrieves measured data from a
FIFO buffer (2, 3, and 4 in the "Program Flow" table). The API specifies the range (Start
No. and End No.), and retrieves the measured data time information (MXDateTime)
and data values (MXDataInfo) from the FIFO buffer. The range that can be specified is
obtained by the data range retrieval function.
Start No.
End No.
First time Second time
* Data up to the end of the specified range may not be able to be retrieved in one data retrieval
process. In this case, the number following the last data able to be retrieved becomes the start
number for the next retrieval process.
FIFO buffer
(MX100)
FIFO buffer
(MX100)
Data range obtained by the API
Processing of retrieved data
instructed by the program.
Start No.*
(Previous
End No. + 1)
End No.
For information about the functions used, see the referring pages in the table below from
the API for the MX100/DARWIN user's manual (IM MX190-01E). See the appendix for
the locations of the program examples.
Programming
Language Reference
Get retrievable data range, get measured data time information, and get
measured data
Visual C++ Page 2-8, "Retrieval of Measured Data (FIFO Designation)"
Visual C Page 3-4, "Retrieval of Measured Data (FIFO Designation)"
Visual Basic Page 4-4, "Retrieval of Measured Data (FIFO Designation)"