UNICOS CMWServer User Manual  9.0.1
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Introduction
EDMS Component version Document generated
2066085 9.0.1 Tue Dec 17 09:28:05 CET 2019

The purpose of manager

CMW is the middleware used in the accelerator sector. CMW is based on RDA (Remote Device Access), data are accesses by mean of

  • device
  • property of a device
  • each property is composed of a set of tags

CMWServer manager acts as a bridge between WinCC OA project and CMW infrastructure, allowing for CMW clients to access values of individual DPEs in WinCC OA project, as illustrated on the following picture:

intro_01.png
CMWServer as a bridge

According to configuration, CMWServer manager performs mapping of individual DPEs to given device & property in CMW realm. The CMWServer supports 3 basic operation types:

  • GET - a client request to retrieve the value of a specific device & property.
  • SET - a client request to set the value of a specific device & property.
  • SUB - (subscription) a client request to be notified of value changes for a specific device and property. Note that in order to receive value updates, a client must explicitly activate a subscription via a subscribe call, similarly, to stop receiving value updates a client must explicitly de-activate subscriptions via an unsubscribe call.

Important terms

It is important to clearly distinguish two very distinct, even though looking similarly, terms:

  • CMWServer manager - a manager in WinCC OA project, like any other managers (CTRL, UI, SIM etc.). The manager can be added to/removed from the project, manager can be started/stopped/killed like other WinCC OA managers. So, it is 'usual' WinC OA manager.
  • CMW server - a server that is registered in central CMW name server(s) and exposes some devices/properties to the clients. So, this is the server where CMW clients can connect and perform basic operations of CMW device/properties, known to this server.

The CMWServer manager is a 'container' for running CMW server. Container can be empty, i.e. CMWServer manager can run and interact with WinCC OA project without creating and starting CMW server. CMW server is only created and started by container is there is valid configuration.

Note
In practice, CMWServer manager tries to start CMWserver immediately when manager is started, if creation/starting of CMWServer was not successful then CMWServer manager will terminate. Thus, the state 'manager is running, but server is not running' can only appear for short time.

Furthermore, after CMW server was created and started by CMWServer manager, it can't be stopped or reconfigured without stopping/restarting the container (CMWServer manager).

UNICOS CMWServer component is installed in existing WinCC OA project just like any other JCOP or UNICOS component: using fwInstallation tool.

Note
New version of CMWServer (based on RDA3 transport) must be fully compatible with previous server (based on RDA2). This means that the new CMWServer manager must work correctlty using configurations made for previous version.
Warning
The implementation of new CMWServer manager is based on DeviceServer by BE-CO which is only available for Linux. By this reason there is no version of CMWServer manager for Windows.