12/11/2023 9:57 PM | |
Joined: 3/14/2008 Last visit: 10/8/2024 Posts: 2109 Rating: (941)
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Hi, No worries if you are new, we are here to help! First let's talk about the way the system works. When the SCL code has been expanded with inputs/outputs and compiled, the updated block cannot be downloaded in run usually. The PLC cannot handle that and this means you need to execute a full download. This will mean all SFC's are going to Idle, and all blocks are started up again via OB100 (Warm restart). Please note that in such cases it's important to execute a readback of the program, meaning all OCM variables (or all values that can be readback depending on the option chosen) are send to the CFC charts in the offline program and those are going to be downloaded to the PLC via the full download. If you do not do this, you could lose those values (parameters, controller settings, monitoring times of valves,motors etc.). There is one exception if you meet the following requirements:
If you meet those requirements, you have an option called TCiR (Type Update in Run). It allows in most cases an update in run which means the program will remain running. There are two cases that you still cannot download in run:
In later versions of PCS7, the default value change has been solved which means there is only one change that cannot be download in run. When you update the block via the master library (should be default procedure for PCS7 projects), you have the option to mark Type Update in Run (if you meet the requirements). The system checks if TCiR is possible. Another option is to insert the block in the project Blocks folder and execute option: Update Block Types in the CFC editor. You get the red warning box, but also a small checkmark to select TCiR (if you meet the requirements). If not, you cannot download in run. This procedure is not recommended because the block is already updated in the project. If you do not meet the requirements for TCiR, there is one trick to be able to download in run. You can change the SCL code, and use a new Block name (with new FB number) to create the updated block. You can import the block in the CFC charts and then reconnect all connections from the old block to the new block. Afterwards, you can delete the old block from CFC charts and Blocks folder and then you can just download in run. It depends if you can use this trick, if you have changed a block type that has over 200 instances, you may ask yourself if it's worth it. By reading your post, I hope it's not too late....if you have already updated the block in the project and you cannot revert back to an earlier backup...you may need a full download... PS: You did not mention the PCS7 version, but only the Step 7 version (which is part of PCS7). But looking at the version you should have PCS7 V8.1 SP1 right? I hope you have a CPU410-5H at your disposal..... |
Last edited by: Oreca at: 12/11/2023 21:59:10Last edited by: Oreca at: 12/11/2023 22:12:22If I could help you, you can use the RATE button. Thank you. |
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12/12/2023 10:00 AM | |
Joined: 3/14/2008 Last visit: 10/8/2024 Posts: 2109 Rating: (941)
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Hi, Correct, the type change is valid for VAR signals as well. Only VAR_TEMP is excluded where the block interface does not change. For a CPU417 the TCiR cannot be executed. The preferred method is using the master library (If you have one). The SCL sources reside in the master library and can be compiled to a block type. In Component View, you can select the block from the Blocks folder of the master library and via tab: Options->Charts->Update Block Types you can update the block. From here you can select all AS projects and check which project must be updated. If you have two AS projects and you only update one, you can get problems with the OS compile because for the same block, two different interfaces can be found. You can also see the impact before you update the block like AS stop is needed or OS compile needed. I cannot say what happens to your plant, but with readback you make sure all operator control monitoring values are read back from the PLC so those are up to date. The entire program will be downloaded to the PLC, all SFC's are going to Idle, all control modules will go to their intitial state->Manual mode. You cannot pause Batch and then continue from there. The whole installation must be started up again. I think you should use the trick to create a new FB and reconnect all interconnections to the new block. This way the system can remain in run. See the following link for more information about the restart of the PLC: AS controller load and restart
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If I could help you, you can use the RATE button. Thank you. |
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