The complete documentation for the DAQ - DCS Communication package may be found at the ATLAS DCS site http://atlas.web.cern.ch/Atlas/GROUPS/DAQTRIG/DCS/DDC/ddc.html
The most substantial news of DDC v. 5.0 included into this release is introducing of a new version of each of DDC applications, except the DDC Configuration editor (the latter is still unavailable). These new application versions use the DIM package for communicating with DCS PVSS projects instead of direct using of PVSS API for that purpose. This is to avoid the dependency on the Linux environment having been used while buiding PVSS API. In further new versions of applications will be mentioned as DIM based while the previous ones as direct.
The direct versions of the DDC aplications are also kept in the release and planned to be supported at least for the year 2005. However, no improvments is planned, except fixing bugs if any. All problems existing in the previous release for the data, message and command transfer are resolved.
Two DDC versions are compatible at the TDAQ side with minor exceptions declared below for data and message transfer. The libdim.so shared library should be available under the directory $DIMDIR/linux. Then it is to be made available for DDC applications with known script install_ddc_libs.sh, modified in this release.
DIM based version of the package requires a PVSS project extension by
In order a DIM based application could be used, the DIM DNS (naming) server must be running on a network. Both DDC segment and DIM manager of PVSS project must refer to this server by DIM_DNS_NODE environment variable. It is recommended to launch DIM DNS server on the computer where the PVSS project to be connected is running.
Details of DIM, its installation and integration with PVSS one can find at http://www.cern.ch/dim/ and http://clara.home.cern.ch/clara/fw/FwDim.html
Appplications are updated to comply with TDAQ configuration and Control interface changes.
No changes
Configuration of DIM manager
New facility
While transfer a structure a subset of its fields can be declared, which
only is to be transferred. The syntax of such declaration: Structure_Name:
[ [, .. ,] field1, [, .. ,] ... fieldN ]
Comma without the name for the omited fields is mandatory unless all of remaining
fields are not to be transferred.
If there is no field specification, the complete structure is to be transferred
like in the direct version. Since DIM based version can not know the names
of the fields, in the case of DCS-to-DAQ transfer the structure fields will
be placed into a specified IS server as Structure_Name.1,
... , Structure_Name.N. In
the case of DAQ-to-DCS transfer with specification of the fields each field
of DP to be received from DAQ must be configured in DIM manager as a separate
Subscribed service.
Note: Such configuration of a structure transfer can be applied also for direct DDC-DT,
but specification of fields will be ignored.
Incompatibility: Cannot transfer in any direction a complete structure including an array, which is not the last element of that structure. For this case one has to declare for DIM manager each element of that structure as a service to be published or subscribed. If DAQ publishes such a structure to be transferred for DCS, the configuration definition with specification of fields should be applied.
The command line to launch cannot comprise the parameter -P pvss_config_path (makes no sense).
The command line interface is changed in accordance with new DAQ Control
interface. The command line looks now like ddc_ct
-p $TDAQ_PARTITION -n controller_name -P parent_name -s segment_name -D pvss_config_path,
where parent_name is
the name of the parent controller, segment_name -
name of the segment controlled by this ddc_ct controller.
While defining a DdcCtApplication object in the configuration DB,
the user should not mention there the controller name, parent name and segment
name
- they will be inserted into the command line of pmg agent automatically.
Configuration of DIM manager
The command line interface is the same like for the direct application, except the last parameter, which cannot be there.
No changes.
Configuration of DIM manager
Incompatibility: There is no possibility to declare transferring all PVSS alerts for DAQ.
The command line to launch cannot comprise the parameter -P pvss_config_path (makes no sense).
All wokstation names, including PVSS stations to connect to, must be defined in Configuration DB by complete network name. Note: While using DIM based package version, IP addresses instead of the network names are not allowed.
In order to use DIM based DDC package, except the command line parameters changes mentioned above, the user has to edit the DDC segment configuration DB as follows:
The API for sending DAQ requests for DCS data changed (for both single read and additional subscription). The parameters of the type string of all of API methods to send a request should now look like <DP element name> | <Service name> => <IS server name> instead of <IS server name>.<DPE name>. This is for precise diagnosis, whether the server name does present.