hist_buffer_id_read (hist_task, queryid[, start[, count]])
The task object corresponding to the Cascade Historian. A task object is created by a call to the Gamma function locate_task, as follows:
hist_task = locate_task ("tfrc/histdb", nil);
The index into the buffer of the first X-Y data pair to be transmitted. Permits access to a portion of the buffer. If not specified, a default of 0 is used.
The number of X-Y data pairs to be transmitted. Permits access to a portion of the buffer. If 0 or not specified, the entire buffer is read.
This function provides a client with access to a buffer of data created in the Cascade Historian in response to a client query. Once created, a buffer remains available in the historian until it is explicitly deleted. This function will automatically segment a request for large buffers (those exceeding a reasonable IPC message size) into multiple partial requests, and will reassemble the segments into the complete resulting buffer in the client's process.
See the example for the hist_exchange_buffer function.
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