Reading an Event Buffer from GE PAC RX7 Controllers

An event buffer can be read using three types of Tags: Event-reported Tags, Event-reported Tags by point, and Real-time Tags.

Event-reported Tags

Event-reported Tags return, at each reading operation, all events stored in Driver's internal buffer, and they can be configured by Strings or numerically.

String Configuration

·Device: "<slave id>:"

·Item: "gesoe0.<Base address of an event stack>"

Numerical Configuration

To read an event buffer from GE PAC RX7 using numerical configuration, users must define, on Driver's configuration window, an operation that uses as its reading function the special function GE SOE. Its data type must be defined as GE_events.

·B1: Slave ID

·B2: Code of the operation defined with GE SOE function

·B3: 0 (zero)

·B4: Base address of PLC's event stack

At each scan on this Tag, this Driver checks if there are events on controller's buffer. If there are events, this Driver starts an event-reading thread, which is executed in background, not blocking the scan of all other Tags. After finishing the reading of a Driver's buffer, this event-reported Tag returns the set of events read on that scan.

Returned events generate a sequence of OnRead events on this Tag. For each read event, E3 updates Tag fields (Element values and timestamp) with values from a certain event, and calls the OnRead event once. This event's script must be defined by users, and it is generally used to insert Tag's data in a Historic.

Every event is represented by a Block with two Elements, with its Timestamp field read from a device. Fields from the respective reading Block Tag are displayed on the next table.

Block Tag fields

For more information about event-reported Tags, please check the specific topic on E3 User's Manual.

Event-Reported Tags by Point

Starting with version 2.5 of this Driver, it is possible to use a new Tag to download events from a specific point.

This Tags works as the previous one, except that it returns only events from a specific point.

Different from the previous event, the returned value only contains a single Element with a status value of a point, so that only one Tag can be used. This Tag must be configured as follows:

String Configuration

·Device: "<Slave Id>:"

·Item: "gesoe<200 + Point's index>.<base address of event queue>"

Numerical Configuration

·N1: Slave ID

·N2: Code of the operation defined with GE SOE function

·N3: 200 + Point's index (for example, for point 2, configure N3 as 202)

·N4: Base address of PLC's event stack

For more information about event-reported Tags, please check a specific topic on E3 User's Manual.

Real-time Tags

These Tags return the most recent event already read for a specific point. These events are stored on Driver's internal memory for each PLC's event reading, with their respective timestamps read from a device. This Tag uses the following parameters:

String Configuration

·Device: "<Slave Id>:"

·Item: "gesoe<100 + Point's index>.<base address of event queue>"

Numerical Configuration

·N1: Slave ID

·N2: Operation Code

·N3: 100 + Point's index

·N4: Base address of PLC's event stack

·Value: Point's status