When I reboot my PLC, the visualization is displayed, but the screen is not responsive for about 1 minute and 30 seconds (screenshot below). I checked the profiler (screenshot below) and noticed that the cyclic programs are not executed during this period (when the screen is frozen).
Based on your expériences, is this behavour normal ?
For the record, I recently updated to the latest AS (4.12) and runtime (K4.93) versions. Previously, I did not experience this behavior; the screen would remain black (loading OS…) or show the GIF until the visualization was displayed (responsive screen).
indeed, it looks quite strange at first sight.
What’s the PLC type, and what type of visualization is used (mappView with a remote browser, or Visual Components)?
And, has anything changed at the hardware configuration (new modules, modules exchanged)? Are there any “unusual” entries in the loggers (not only errors but also info / warning, for example about “firmware xxx update”)?
I experienced this once with a mappView visualization. My problem was caused by improper OPCUA tag configurations. I was able to find this via the logbook (enable visualization logs). Hope this helps.
Thanks to your support, I have found the cause of this behavior.
I am using a C30 with a Visual Component VC4.
Recently, I was testing remote update using BackUp mapp. For this test, I created an FTP server on another C30 and placed my boot package there.
In the program, I configured the settings as shown in the screenshot below. The test worked perfectly.
I believe that rebooting the PLC without having the FTP server on the network triggers this behavior (delayed restart). When I removed the Enable statements in the INIT program, everything returned to normal.
yes, that makes sense.
I assume that the function “stuck” in the DevLink() call for some timeout time trying to reach the FTP server.
That the function is called in INIT explains why AR haven’t reached cyclic mode for the duration of this timeout: the AR doesn’t switch to cyclic mode not until all INITs of all task classes are executed after reboot, and INITs are not monitored regarding code execution time.
So, as long as INITs are executing, no cyclic operation is done by the PLC, and since the VC4 “drivers” start as part of the operating system, the display is already shown but isn’t responsive until INITs are done.
Many thanks for sharing your findings and solution!
Best regards!
