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Possible to automatically generate DBs from SCL?

Created by: rickardg at: 2/17/2010 1:14 PM (5 Replies)

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2/17/2010 1:14 PM	Rate (0)
rickardg Posts: 18 Rating: (1)	Hi I'm a beginner with PLCs, I'm checking out Step7 to see if it possible to use a S7-400 (or 300) PLC in a project I'm working on, I'm using SCL and have some problems with data blocks. In my program I would like to have one DB with configurations only (stored in non volatile memory) and this DB should not be connected to a specific FB as it is used by several FBs and I don't want anything but the configuration inside it, then other DBs for local variables etc that is usd by the FBs. My problem is that the configuration in a quite long list, so it is hard to create the datablock by clicking and adding variable by variable. It seems that sometimes the SCL compiler can auto generate DBs connected to FBs but then it adds local variables etc in it. I would like to declare the DB stand alone something like: [code]DATA_BLOCK logic_config VAR input_list ARRAY[0..8191] OF WORD; block_list ARRAY[0..8191] OF STRUCT typ : BYTE; inputs: WORD; input_index: WORD; END_STRUCT END_VAR END_DATA_BLOCK[/code] and then use it from other code like: [code]my_index:= logic_config.block_list[logic_pos].input_index; my_input := logic_config.input_list[my_index]; [/code] But it doesn't seem to be the way independent data blocks should be declared
rickardg Posts: 18 Rating: (1)
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2/18/2010 12:59 PM	Rate (0)
smiffy Platinum Expert Joined: 1/17/2007 Last visit: 3/23/2023 Posts: 1523 Rating: (518)	I have never tried it in SCL, but it is quite easy to define a DB in STL. The attached code shows you how. Obviously, you would need to define the DB_NUM symbol in the symbol table as datatype DB n and address DB n (where n is the DB number you want to create). The TITLE line text is seen as the comment for the DB. [code]DATA_BLOCK "DB_NUM" TITLE = Auto generated DB VERSION : 0.1 STRUCT WORD1 : WORD := W#16#1234; WORD2 : WORD := W#16#ABCD; INT1 : INT := 6000; INT2 : INT := 1234; END_STRUCT ; BEGIN END_DATA_BLOCK[/code]
	Programming today is the race between software engineers building bigger and better idiot proof programs, and the universe producing bigger and better idiots. So far, the universe is winning...
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2/18/2010 8:32 PM	Rate (0)
Oreca Platinum Member Joined: 3/14/2008 Last visit: 3/27/2023 Posts: 1913 Rating: (834)	Just like you can insert a block call: FB or FC, you can also insert a DB call. Below is an example: Example DATA_BLOCK DB20 STRUCT // Declaration section VALUE:ARRAY [1..100] OF INT; END_STRUCT BEGIN // Start of assignment section : END_DATA_BLOCK // End of data block Also check the document in this link and check page 5-18 and on. It will give you some more info http://www.kar.elf.stuba.sk/predmety/pkom/Literatura/S7scl__b.pdf
	If I could help you, you can use the RATE button. Thank you. Prospact Netherlands...your PCS7 Expert Topic: PCS7 Complete Overview Please check out the following topic with information we need from you before you create a new topic: Topic
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2/22/2010 2:44 PM	Rate (0)
rickardg Posts: 18 Rating: (1)	Great, that seems to work, thank you very much
rickardg Posts: 18 Rating: (1)
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12/3/2019 10:09 AM	Rate (0)
rfp1997 Posts: 35 Rating: (0)	Hey, comeback after a few years. Can you attach this file, please? I can't access the shared link. Thank You. Regards, RFP
rfp1997 Posts: 35 Rating: (0)
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12/3/2019 10:52 AM	Rate (0)
SOble Gold Member Joined: 9/16/2013 Last visit: 1/5/2023 Posts: 511 Rating: (104)	rfp1997 Hey, comeback after a few years. Can you attach this file, please? I can't access the shared link. Thank You. Regards, RFP Hello rfp1997, The procedure would be: Create empty SCL source Open your SCL source Go to Insert -> Block template -> DB There you go, example of DB created inside SCL: .txt has been attached as well DATA_BLOCK DB14 STRUCT IA_S2 : REAL; //Operat. meas. current A side 2 [kA] (724) IB_S2 : REAL; //Operat. meas. current B side 2 [kA] (725) IC_S2 : REAL; //Operat. meas. current C side 2 [kA] (726) Vab : REAL; //Va-b [kV] (624) Vbc : REAL; //Vb-c [kV] (625) Vca : REAL; //Vc-a [kV] (626) P : REAL; //P (active power) [kW] (641) Q : REAL; //Q (reactive power) [kVAr] (642) f : REAL; //Frequency [Hz] (644) S : REAL; //S (apparent power) [kVA] (645) IA_S1 : REAL; //Operat. meas. current A side 1 [kA] (721) IB_S1 : REAL; //Operat. meas. current B side 1 [kA] (722) IC_S1 : REAL; //Operat. meas. current C side 1 [kA] (723) Va : REAL; //Va [kV] (621) Vb : REAL; //Vb [kV] (622) Vc : REAL; //Vc [kV] (623) END_STRUCT BEGIN END_DATA_BLOCK Best Regards Soble Attachment DBfromSCL.txt (100 Downloads)
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