Not knowing what else to do, I asked the client if he could send me his HMI and PLC programs so I could do some testing in house.
He graciously agreed, and what I found was pretty strange – something I had never seen before.
On boot, I was getting a message saying, “Loading symbol from RSLinx Enterprise, please wait.”
This message seemed to coincide with the clients suspicion that the large number of end user aliases in the controller may have been the culprit. And the next message I received (after over 5 minutes) seemed to be confirming that.
It said, “Updating controller symbols has timed out. You may choose to continue updating controller symbols or run the application. Start-up macros and datalogs may not operate correctly…”
Adjusting the processor's (L73) overhead time slice to 50% did provide some improvement. At that setting, I no longer got the timeout message.
However, something really bothered me about the message I was getting… the client only have about 30 tags in his project, so what was RSLinx Enterprise taking over 6 minutes to load?
Surely 30 tags would load in a fraction of a second, so it must be trying to load something else, but what?
Having exhausted all my ideas, and with the system issue successfully duplicated, I once again contacted tech support.
This time the tech I spoke with found an undocumented note about PVPlus slow boot times coinciding with large numbers of devices in the Target Tab in RSLinx Enterprise.
Now you may ask, why would anyone have anything besides the target PLC in the target tab?
Well not everyone is able to commission their HMI's prior to installation. And if you're connected to the plant network when you browse for your PLC in RSLinx Enterprise's local tab, you'll also see ALL the other Rockwell devices on the network too.
An unfortunately, the “copy from local to target” button doesn't just copy the devices that have a “shortcut assigned.”
No, for some unknown reason (well, unknown to me at least) it copies everything from the local tab to the target tab…
With this little tidbit of information, I deleted all the “extra devices” from the target tab, leaving just the PLC assigned to the shortcut.
And presto, the PanelView Plus booted up in a normal amount of time.
Hopefully after a little prodding from myself, Tech Support will write up a public tech note so others who run into this issue won't have to go through as many hoops to find the solution.
Sincerely,
Shawn Tierney
Automation Instructor and Blogger
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