set_point_queue_depthset_point_queue_depth — sets the depth of the DataHub instance's per-point queue for
Gamma.
set_point_queue_depth (N)
NAn integer defining the depth of the queue.
t on
success, otherwise an error message.
The DataHub program has a special queueing mechanism for point changes that get sent to the Gamma engine. If a DataHub instance receives incoming point changes faster than the Gamma engine can process them, it puts the new values into a queue for that point. When the Gamma engine is ready to process the next value of that point, it receives the earliest value from that queue, then the next value, and so on, in time-sequential order.
This function allows you to set the depth of this queue, in other words, the
number of values per point that the DataHub instance will store in the queue. The
default depth is 3. We recommend setting the queue depth as
small as possible, since a deep queue will decrease the Gamma engine's
response time. If you want to minimize the response time and always use the very
latest value, you can set N to 0 or
1, which effectively eliminates the queueing behavior
altogether.
See also
get_point_queue_depth and
get_point_queue_count.