Can anybody tell me why 800xA 5.1 pg2 graphics elements have red cross mark while downloading.
System :5.1,Controller:PM866,Network Configuration: Domain,
System Load:73%,Cyclic Load :48%.Controller heap:60.25%
Actually problem occurs While downloading changed programs in to controllers red Cross Mark Appear on all pg2 Graphics Elements for 8-10sec.. as mentioned above System Load,Cyclic Load and Controller Heap are within a limit and even network is working fine as i observed pinging less than 1ms.what would be the problem???
can have some suggestion from experts??
Planning to download Firmware once again in to controllers not sure problem will resolve by this action.
You are getting red cross on graphic elements may be controller stop time is more during online down changes that may be following reasons.
1.May be application size is big & no. of applications are less.
2.When the application has been downloaded,available memory in the controller should be at least twice the application size. The reason for this is that when changes are downloaded, the application running in the controller will be duplicated, along with the new downloaded changes.
Hence, at a certain point there will be 'two' applications, plus the new changes, in controller memory at the same time, thus the need for at least twice the memory
size. When the new application has been fully built, the old application will be
removed from memory.
3.A rule of thumb is: never download an application,so large that it cannot be downloaded to the controller twice.
4.Memory required to download for the change is less.
Note:always try to make more application since loading more applicaitons will reduce the controller stop time & you gain more space fo code execution.
Please refer the manual attached
It does sound like your controller is either overloading during the download or the stop time is excessive.
The "Stop Time" is related to the amount of Free memory and the Size of your largest compiled application. You must have free memory greater than the size of your LARGEST application.
- 1 application will need 50% free memory
- 2 applications eg 5MB and 3 MB must have 5MB free memory
Obviously, you can fit more code into a controller by breaking it up into smaller applications. if you do not have enough memory, then the apllicaiton is downloaded in parts and the stop time can be many seconds.
Your cyclic CPU load must be less than 70% , and preferably should be less than 50%. A large amount of MMS or OPC communications may mean you have less cyclic load available because your system load starts to exceed 30%. If your total CPU load is over 85% or so then you should start to consider this controller as being close to "full".
Cyclic load can increase by a very large amount when you cold or warm start an application because the "Start_" code blocks execute. Check your CPU load during the download. "Start_" blocks often do a lot of string handling ( eg names and descriptions) which is very inefficient and uses a lot of CPU time. ( This is why you should not do string handling in the controller). If your free memory size is OK, then this is the most likely cause of your problem.
if the OPC subscription status goes bad, then it can take some time ( typically the 8 to 10 seconds you see) for the subscriptions to come good again.