ALPHA-VISION® AvReplay: Introduction

Introduction

SUMMARY

Tables like ‘Archive’ and ‘EventLog’ that have been recorded during Runtime may be replayed.

CONTENTS

1. Overview
2. Prerequisite
3. System Characteristics

Overview

AvReplay allows to read back recorded tables of the type ‘Archive’ and ‘EventLog’ to the runtime system and play back the recorded data.
The replay may run in realtime, fast= or slow motion even single step is possible.

Prerequisite

Table names are no fixed, but the structure of the file must be that of the '_archive.dbf' resp. '_eventlog.dbf' .
It always must be a Archive – EventLog pair of tables.
The consistency of the files is not checked.

The pair of tables are merged to a Replay List sorted ascending by time. Displayed are the PointId, the Description, the Event Type, the Status und Value.

see also - Operation

To use the functionality of AvReplay the appropriate project must be running (Prcs.exe).
When the tables are read in it is checked for the stored Object Numbers to be available in the loaded project.

System Characteristics

The events available for replay are limited to the change of value, status, limits and delay in/out (Column Event Type).

When creating the Replay List the inputs from the Eventlog got priority:

• If, for the same object, at the same second, a value/status change is logged in the EvenLlog AND the Archive, that one from the EventLog has priority.
• If, after inputting all EventLog entries for a second, entries from the Archive for other objects and the same second left, there are appended to the list right after that of the EventLog.

On startup of the reply mode all objects are set to status 'undefined'.

At runtime of „Prcs.exe" and "AvReplay.exe" the imported Alarms are sustained, i.e. after reset and set of the replay modus any objects are on status 'undefined' but the Alarm List of the previous session is still there .
To reset the Alarm List both programs must be closed.

During reply the system again writes a '_archive.dbf' and a '_eventlog.dbf'.

The replay of the List Entries is similar to the runtime, according to this in advance of setting a value an OLD – NEW compare is performed. Under certain circumstances that might cause that an entry is not set explicitly, e.g.:

• If the first status change from the replay list would set an Mp/Po to status 'undefined'.
  Since on startup of the replay modus the status of any object is set to 'undefined' a status change does not take place.
• If, when creating the project, it was defined that status changes for a certain object are not written to the EventLog.
  That means: there might have been a status change that is not captured in the EventLog; i.e. a reaction depending on a status change of that object will never take place.