The operation mode of DncDataSet are shown below.
This mode allows DncDataSet to function as
a FIFO (First In First Out) buffer.
In FIFO buffer mode, data additions always follow the last added data,
and data reads from the buffer always start with the oldest data.
■Image of writing in FIFO buffer mode
As shown below, if 3 more data are added to the buffer in which 6 data are written in total, the data will be added to the end.
If you try to write more than the buffer capacity, an overflow error will occur.
■Image of reading in FIFO buffer mode
As shown below, if 3 data are acquired for a buffer in which a total of 9 data are written, 3 data will be acquired from the beginning.
The data in the buffer is pre-packed by the number of data read.
This mode allows DncDataSet to function as
a RING buffer.
The data is written sequentially, and when data is added beyond the buffer
limit, the old data is overwritten and stored.
Data is read relative to the final data position.
Please use it when you want to always acquire data and acquire values before
and after some event.
■Image of writing in RING buffer mode
When data is written in RING buffer mode, it will be added to the end like FIFO.
If you try to write data beyond the buffer limit, an overflow error will occur in FIFO buffer mode, but in RING buffer mode, older data will be overwritten.
*
It is assumed that the buffer capacity of DncDataSet is 9 data.
■Image of reading in RING buffer mode
When data is read in RING buffer mode, the specified number of data will be acquired based on the final write data.
If you specify 1 data set (3 data) data in the following buffer state, you can get the data of No.06 to No.08.
It is a mode that always keeps the latest
value of the linked data from DncDaq.
Please use it when you simply want to acquire the linked data from the
code.
* Data can be acquired/written in the image of accessing variables from
properties.
