downloads into multi-master systems

andyr 9 years ago in IQANdesign updated by Ulrik Zakariasson (Software development) 9 years ago 1
when downloading a modified application file into a multi-master system would it be possible to introduce the option to only download into one (or more) of the masters rather than the whole system- if the application is very large and the modification is only to the application file in one master, it wastes a lot of time downloading the complete file with an unmodified application file into the other master(s).
Better still how about introducing on-line editing for making simple changes and for de-bugging!!
System integrity is crucial when dealing with multi-master systems. We have several mechanisms to make sure all masters are running compatible applications. Each master runs its own application, but it depends on a lot of common and shared information.

Examples of common information:
  • Modules
  • Measure groups and items
  • Adjust groups and items
  • Logs
  • Languages
  • Access levels and users
Examples of shared information:
  • APPOUT channels
  • Channels connected to display controls on another master
Even a small change in an application may imply a change in any of the other applications. For example, adding a channel to a function group may change the index of another channel that is used by a different master.

However, we try not to send more than absolutely necessary to each master. A project file is therefore split up into several segments. Only segments that have changed are sent.

If you're making a lot of changes to one of the applications only and don't care about data from other applications, you can prevent updates to other masters by physically disconnecting them. When you send the project file, you will be warned that some modules are missing, but it is possible to proceed and send to the ones that are available. When the system is rebooted, it will detect mismatches in system integrity and stop all communication on master and diagnostics buses, but each master will run its application isolated from the rest. If you're OK with that you can use this workaround.

The idea of being able to do online editing is enticing, but of course even more complex.