Compatibility in zenon – exploit potential, carry out updates easily and efficiently (part 2): an example
The compatibility mechanisms in zenon make it possible to use different versions of the software in a network structure. This way the overall system is available at all times when a version is changed – even if individual computers are switched off during the software administration.
An example involving a conveyor system
The system consists of three individual projects: feed-in, storage and feed-out, which are connected via an integration project. The individual projects each have a redundant server pair and a total of 15 connected clients. The additional zenon Web Server provides the project with five web clients on the intranet. The proven zenon version 6.xx is used.
Without the compatibility in zenon, an update would be as follows: the user would have to convert all data into the desired version with the zenon Editor. At a defined point in time, they would shut down the whole system in order to install the new version – at the same time as far as possible. Then they would transfer the converted data and the whole system can be started again. Now the new version is tested: if any noticeable problem arises, the whole system must be searched to identify the cause. In the worst case, the whole system must be moved back to the original version in order to restart production.
Thanks to the compatibility mechanisms in zenon, a zenon update is much more relaxed and can even be carried out during operation: zenon Runtime can operate with the project data from older versions without conversion with no problems at all. A connection to a server running or communicating with older versions is also possible. In practice, this means that each computer can be updated without changing the project. In doing so, the individual stations are only offline for the duration of the installation. The whole system remains available during the updates and the stations continue to be operable. Another advantage is that the alarms and archive logging are also retained and are safeguarded, because the server is also completely available thanks to redundancy.
If the current version of zenon is installed on all computers, the project conversion can be started. It is sufficient to open the projects with the zenon Editor: when reading back project backups from older versions, the project data is automatically converted upwards after you are requested to confirm you want to do this. Now the user only needs to import the settings configured in Runtime, such as user passwords or recipes, and then create the Runtime files for all projects. If these are transferred to the respective server by the zenon Editor, they can be updated without interruption using the “Hot Reload” function: this function integrated into zenon automatically distributes the updated project data from the servers to the connected clients. An identical project status is therefore available on all networked zenon stations. With the method described, all Runtime computers are updated to the current version in the first stage and then the Runtime files are converted to the desired version with the zenon Editor in the second stage.
In addition to the above-mentioned compatibility mechanisms, zenon also offers backward compatibility: if companies use a current zenon Editor, they can also read in project backups from older versions. The Editor files are automatically converted to the respective version in the process. It is therefore possible to work with the most recent zenon development tool, to benefit from the latest functions and to also create Runtime files for older Runtime versions with the current development tool. To do this, it is only necessary to set the target version in a selection box in “Project properties”. The Runtime files created this way can then be transferred to the older systems and used there.
The compatibility that zenon offers provides companies with the freedom to plan migration strategies on a long term basis and to quickly react to market trends. The administration and maintenance of existing systems is thus very easy and also very safe.