S7 memory bottleneck
- Thread starter PLC_talk
- Start date
Francie Bellew
Member
One option is to compress.
Werner
Member
Optimize software. Use STL in stead of FBD blocks.
L D[AR2P#0.0]
Lifetime Supporting Member
When the diagnostic buffer is open on the selected event, there is usually some help available associated with the event id. What is the event id in this case ?
Francie Bellew
Member
Its been a while since I've used an S7-PLC. If i remember correctly when you get this bottleneck messgae in your buffer it gives an option to compress memory?
L D[AR2P#0.0]
Lifetime Supporting Member
Can you clarify where/when you get the bottleneck message ? - in the diagnostic buffer of the CPU, or, in a message box that comes up when you are downloading blocks ?
L D[AR2P#0.0]
Lifetime Supporting Member
The memory bottleneck is referring to the memory space available in the plc. Each time you edit and download a block, the new block will be copied into a new area of memory and the old versions memory will be released - this (over time) leads to memory fragmentation. The memory can be compressed to release the fragmented memory. (From Siematic manager Ctrl+D, the select the memory tab where compress is available). I'm not familiar with a 400H type system so there may be some pecularities with memory compression for these type of systems.
Of course, you could actually be running out of memory as well...
Of course, you could actually be running out of memory as well...
For S7-400, three possible reasons:
1. like "L D[AR2,P#0.0]" says, you have to compress the memory.
You do this when you are online with the PLC and display the Module Information.
2. On some versions of S7-400, you have to plug a RAM memory card to utilise all the memory that the CPU can address.
3. Your program is too big to fit on the CPU. In the offline project, go to "blocks" in the project tree, right-click and open up the properties. You can see how much memory code and data take up. Add 20% to allow for HW Configuration and comms jobs.
1. like "L D[AR2,P#0.0]" says, you have to compress the memory.
You do this when you are online with the PLC and display the Module Information.
2. On some versions of S7-400, you have to plug a RAM memory card to utilise all the memory that the CPU can address.
3. Your program is too big to fit on the CPU. In the offline project, go to "blocks" in the project tree, right-click and open up the properties. You can see how much memory code and data take up. Add 20% to allow for HW Configuration and comms jobs.
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