Applies To:
  • CitectSCADA

I see in the readme file for 5.31 it states the following:

" Trend Server Compatibility

Where possible Citect Version 5.31 has been designed for compatibility with previous versions of Citect, in order to support staggered upgrading. Some areas of communication have been disabled where maintaining compatibility has not been possible. Specifically:

- Version 5.31 Trend Servers are compatible with Version 5.30 I/O Servers.

- Version 5.31 Trend Servers are not compatible with Version 5.30 Display clients.

- Version 5.31 Display Clients are not compatible with Version 5.30 Trend Servers.

- Version 5.31 Trend Servers are not compatible with Version 5.30 Trend Servers for redundancy purposes.

- Version 5.31 Trend Servers can use Version 5.30 history files.

So what is the best procedure to upgrade a project to 5.31 and above?


The recommended procedure really depends on the configuration of your Citect system.

Configuration 1:

- 1 I/O, Alarm, Report, and Trend server on a single PC

- multiple Display Clients with linked projects to a file server or a copy of the project on their own PC

With this type of configuration it is not critical that the system is always up and running since you do not have redundancy so you should:

a. schedule a time to shutdown of ALL Citect nodes.

b. upgrade the server first and bring it back up.

c. go around to each Display Client and upgrade it and bring it up.

Configuration 2:

- 1 or more pairs of redundant IO

- a redundant pair of Alarm, Report, and Trend servers

- multiple Display Clients

This is a bit more tricky because a 5.2x trend server will not sychronize with a 5.31 and above trend server so you have to do a bit more work:

(a) If you are using Display Clients and servers that are linked back to a file server and you have a redundant file server (i.e. backup project path) configured you should disconnect the primary file server PC from the network and change pages on all the Citect nodes to make them switch to the redundant project path. It is important to change pages on the Display Clients to force it to switch over to the standby file server. You don't want to upgrade a file server to 5.31 and then have a 5.2x Display Client pulling graphics file off of it. You could get unexpected results. The other option is to notify all nodes not to change graphic pages during your upgrading of the system. Once that is done, upgrade the file server and put it back on the network. If you do not use linked projects, proceed to (b).

(b) Shutdown the primary trend server. This will cause all your 5.2x Display Clients to switch to the backup servers which are running 5.2x. Upgrade the primary trend server to 5.31 (or 5.4x). When you bring it back up it will not synchronize with the standby trend server so you'll have a gap in your trends on the Primary server only. Your 5.2x Display Clients will still be looking at the Standby Alarm, Report, and Trend server (which is still 5.2x) because they do not switch back when the primary comes back online.

(c) Shutdown, upgrade, and bring back up the Primary Alarm and Report Servers

(d) Shutdown, upgrade, and bring back up all Display Clients (remember on startup now the Display Clients will connect to the primary servers including the primary file server which is good because everyone is at same version).

(e) Shutdown, upgrade, and bring back up the Standby Alarm and Report Servers

(f) Shutdown, upgrade, and bring back up the Standby Trend Server. This trend server will synchronize with the Primary server because they are both now the same version.

(g) Upgrade the standby file server. If you do not use linked projects, proceed to (h).

(h) Now that everyone is on the same version you still have a gap in the trends on the Primary Trend Server and the Standby Trend server does NOT have a gap. To get rid of the gap on the primary you'll need to shutdown the Primary Trend Server and first copy over all the .HST files from the Standby Trend Server and then copy all the data files. YOU MUST COPY THE HST FILES FIRST see KB Article Q1265 . If you have a lot of trends the easiest way to do this is via the DOS command XCOPY. Go to the Command Prompt and go to the directory you want to copy from and type in "XCOPY *.HST <destination> /s" and then execute "XCOPY *.0* <destination> /s". It will copy all the HST files with subdirectories (that's the /s option) to the destination.

(i) Start the Primary back up and the Trend backfill will occur and you'll have no gaps in your trends.


It takes careful planning when upgrading a system. Be sure to read the readme.doc file of the new version you are going to upgrade to and also check the online help for "Upgrade Information" prior to starting any upgrade. As always it is a good idea to backup all projects and trend data in case you have to resort back to a previous version.