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Created by: owkenobi at: 1/18/2012 8:47 AM (11 Replies)

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1/18/2012 8:47 AM	Rate (0)
owkenobi Posts: 3 Rating: (0)	Hello, I'm working on a project with TIA Portal V11 and a315 PN/DP CPU and I'm trying to figure out how to declare/create enumerations. Searched everywhere from Siemens manuals to online forums, search engines and so on... but nothing found. Is there a way to create our own enums or is something missing? Thanks in advance for your help. Best regards, owkenobi.
owkenobi Posts: 3 Rating: (0)
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1/19/2012 11:07 AM	Rate (0)
Denilson Pegaia Platinum Expert Joined: 9/23/2005 Last visit: 1/30/2023 Posts: 4177 Rating: (1324)	Hi, What you mean with "Enumerations"?
	Denilson Pegaia Siemens Industry Sector Technical Support
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1/19/2012 3:47 PM	Rate (0)
owkenobi Posts: 3 Rating: (0)	Hi Pegaia, Taken from B&R help: "Declaring the Enumeration data type specifies that the value of each data element of this type can only be one of the values in the respective list. The enumeration list defines an ordered amount of enumerated values,beginning with the first identifier on the list and ending with the last. By default the first enumerator is assigned the value 0, and the value of each subsequent enumerator is increased by one. Variables, or enumeration data type elements are internally mapped as DINT. Their value range is determined through the DINT value range (-2147483648 ... +2147483647). This enumeration data type must be declared between the keywords TYPE and END_TYPE: TYPE Color : ( red, yellow, green ); END_TYPE " Hope this helps to explain what enumerations are. Thanks in advance, owkenobi.
owkenobi Posts: 3 Rating: (0)	Last edited by: owkenobi at: 1/19/2012 3:49 PM
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1/20/2012 10:45 AM	Rate (1)
Denilson Pegaia Platinum Expert Joined: 9/23/2005 Last visit: 1/30/2023 Posts: 4177 Rating: (1324)	Hi, There is no Enumerations in the STEP 7 (at least yet). The nearst that you can go is to define constants in the tag editor...
	Denilson Pegaia Siemens Industry Sector Technical Support
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1/20/2012 11:00 AM	Rate (0)
owkenobi Posts: 3 Rating: (0)	Thank you Pegaia, your help has been invaluable. Regards, owkenobi. P.S. I hope Siemens will add enumerations in TIA Portal V11 SP3 or V12, I think it wil be very useful.
owkenobi Posts: 3 Rating: (0)
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1/20/2012 3:00 PM	Rate (1)
0_Einstein Diamond Expert Joined: 7/7/2010 Last visit: 1/27/2023 Posts: 13080 Rating: (2123)	owkenobi Thank you Pegaia, your help has been invaluable. Regards, owkenobi. P.S. I hope Siemens will add enumerations in TIA Portal V11 SP3 or V12, I think it wil be very useful. You can create a structure: define structure "Color" .red = SINT, initial value = 1 .blue = SINT, initial value = 2 .green = SINT, initial value = 3 If you have constants as Pegaia suggests, it will work similar, but in this way, the definitions are consolidated all together. You can then say, "if somevalue > 1000 then move Color.red to HMI.screen1.tankcolor" (or something similar). Note this is just pseudo-code.
	science guy
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This contribution was helpful to 2 thankful Users qualbuonbomb Lorenzo_Bo

9/25/2014 6:38 PM	Rate (0)
qualbuonbomb Advanced Member Joined: 7/11/2014 Last visit: 9/20/2022 Posts: 20 Rating: (4)	It seems to be a very good idea. But, what do you mean with "structure"? Do you mean data type? Attachment Immagine.jpg (346 Downloads)

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9/26/2014 8:47 AM	Rate (0)
qualbuonbomb Advanced Member Joined: 7/11/2014 Last visit: 9/20/2022 Posts: 20 Rating: (4)	qualbuonbomb It seems to be a very good idea. But, what do you mean with "structure"? Do you mean data type? Ok, I'm sorry for the question. Struct is just struct, and not data type. The issue is that it's not possibole to declare struct (neither user defined data type) as constant, neither in FB/FC neither as global memory, and this is not 100% elegant. Anyway the best solution to obviate...

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9/29/2014 3:58 PM	Rate (1)
0_Einstein Diamond Expert Joined: 7/7/2010 Last visit: 1/27/2023 Posts: 13080 Rating: (2123)	qualbuonbomb qualbuonbomb It seems to be a very good idea. But, what do you mean with "structure"? Do you mean data type? Ok, I'm sorry for the question. Struct is just struct, and not data type. The issue is that it's not possibole to declare struct (neither user defined data type) as constant, neither in FB/FC neither as global memory, and this is not 100% elegant. Anyway the best solution to obviate... In the PLC world, your definition of elegant and other experienced PLC developers may be very different because of the nature of what PLCs do versus what generic purpose computers do. Elegance in a PLC program is getting it do something that is easily understandable, easily maintained, low scan time, low memory use, fast communications, and intuitive end user experiences. The "how" is what you and I are tasked with. Knowing that recursion is often a method to accomplish this in the PC world can solve seriously hard problems - meeting all the above criteria except perhaps memory use - does not help. Knowing hold to solve a naturally recursive problems using a PLC can be elegant when does over multiple scans or using additive algorithms where the solution is available after a certain number of plc scans rather than slow it down to solve it completely this scan just to have the user not care for minutes or hours later. Elegant might be not to solve the problem at all and simply approximate the solution and then iterate each plc scan to a better solution until it is within tolerance. It does require is to think differently and use the instructions available, and when necessary, request new instructions to solve a different class of problems currently too difficult to do efficiently without making the code really hard to understand and maintain (for others coming behind us). I know I have not really answered your question, but you posed elegance is not available. I say it can be if you simply redefine your programming framework to specific purpose rather than general purpose computing.
	science guy
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This contribution was helpful to 1 thankful Users qualbuonbomb

9/29/2014 6:06 PM	Rate (1)
qualbuonbomb Advanced Member Joined: 7/11/2014 Last visit: 9/20/2022 Posts: 20 Rating: (4)	Ok, the word "elegant" moved the discussion from solutions to opinions... I think that enumerators are very helpful to edit comprehensible code. It help to understand, for example, if the status of the line/machine is “INITIALIZING”, “RUNNING”, “IN_PAUSE”, “LOADING”, or “UNLOADING” and not “0”, “1”, “2”, “3”, “4” or “5”. It’s up to the compiler taking care of the conversion and it does not load the CPU of more work, memory and so on. The solution you gave needs to allocate new variables, many variables that contains only constant! Also, when you define a list with dozens or hundreds of elements it becomes easy to duplicate the initial value (especially if copy and paste are used). That’s a dangerous weak point, because the compiler will never warn you, and it’ll cause disease hard to debug. That’s why I think it’s not elegant. Furthermore yes, enums are used in PC programming, also the instruction "+" or "-", but it's not meaning that "+", "-" and enums are made for PC programming. It's mathematics, and mathematics is used in physic, statistics, organization, and… why not? PLC programming! Thanks for your suggestion. I have already stolen it! It seems to work.
	Last edited by: qualbuonbomb at: 9/29/2014 7:12 PM
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