Maxiflex P3 PAC User Manual
59
-© Omniflex
UMM126XR18.pdf
9. Queue Service Explained
9.1 Introduction to the Queue Service
The Queue Service is best described as a circular buffer of memory that contains blocks of
formatted data referred to as queue records. The Queue Service provides a buffering interface
between processes that produce queue records in real time and processes that consume those
queue records in non-real time. A typical example of a SCADA system on PC, collecting time
stamped event information in non-real time from a Maxiflex System configured as a Sequence of
Events monitor, that is detecting events in Real Time.
The Maxiflex System makes use of the M176xA 32SOE modules to perform this function. These
modules are scanning digital inputs for any change in their state
(either ‘1’ or ‘0’). When such an
input does change state, this occurrence is called an
event
. Events are time stamped with the
Date and Time of the event and a queue record is created that is then sent to the Queue Service in
the P3 CPU. The SCADA system, by means of the Omniflex Conet OPC Server, is able to retrieve
these events from the Queue Service for analysis at the SCADA.
