5/18/2016 12:35 PM | |
Posts: 24 Rating: (1) |
Dear Experts, What is the basic difference between SFC and SFC types? It would be helpful and clear if you could provide me with examples. Thank you. |
5/18/2016 12:50 PM | |
Joined: 3/14/2008 Last visit: 9/20/2024 Posts: 2095 Rating: (936)
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hello jigarhg, Are you ready? Here it comes: The main difference is that SFC types are mainly used by the PCS7 Add on: Batch. This is a higher level system which controls the system by executing recipes. Batch works according to ISA88, where there is a process cell->unit->equipment->control module. A SFC type can represent an equipmentmodule like an agitator. However, using SFC type is not limited to Batch only. The main difference is that a SFC type is setup once, and multiple instances can be inserted in CFC charts. For an SFC chart, there is only one. You can setup a SFC type uniform, which means you cannot address objects directly. You can configure so called characteristics like block contacts, setpoint, parameters etc. which you use in the SFC type. When you have your SFC type complete, you can distribute instances of that SFC type. With a SFC type, you can also create control sequencers like CS1: Stir, CS2: Heat, CS3: Cool. When you have 10 tanks which have the same functionality, you can create one SFC type and use 10 instances. A SFC type is expandable with IO's, which you define in the "Characteristic" overview. You can define parameters, setpoints, block contacts, operator text etc. For the so called block contacts, you can define objects of type valve, motor, PID etc. When you insert the instance, you can connect your process tag to the objects you defined and a connection is made. A SFC chart is a basic SFC which cannot be expanded. In a SFC chart, you can address objects directly. You cannot use characteristics. A SFC chart works in the same way like a SFC type-instance. You can set it to run, stop, abort etc. according to the so called: SOL logic. A SFC chart has no CFC block. It only has an SFC editor with an external view. A SFC type has a CFC block which you can drag in a chart. What differs more is that a SFC type can have 64 sequencers, where a SFC chart can only have 8. So basically: When you have multiple units with the same functionality, it's better to create an SFC type. When something has to be changed, a SFC has to be changed once and can be updated throughout the project all at once. When you have unique functionality or easy functionality, you can use a SFC chart. Usually, a SFC type needs more engineering time. I prefer to use SFC types always, because I'm used to them because of the Batch knowledge. Please see the attachment for a visual schematic of the SFC type |
Last edited by: Oreca at: 5/18/2016 1:04:30 PMLast edited by: Oreca at: 5/18/2016 1:08:42 PMIf I could help you, you can use the RATE button. Thank you. |
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5/18/2016 12:51 PM | |
Posts: 567 Rating: (107) |
Hi, have a look in chapter 3 "introduction" and chapter 4 "Getting Started" of the SFC Manual. Link to the Manual: https://support.industry.siemens.com/cs/ww/en/view/109736726 |
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