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FB Works as Long As I don't Call it 1st.....

Created by: OUFAN75 at: 6/22/2012 3:51 PM (6 Replies)

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6/22/2012 3:51 PM	Rate (0)
OUFAN75 Posts: 21 Rating: (1)	Good Morning, I created my 5th FB in my project with one rung of logic and when I call it as the first block in OB1 download it, it is green on the EN but the ENO is red (See attachment). When I move the call to anywhere else as long as it's not called first, it works and both EN and ENO are green as they should be. I am scratching my head on this one on why it matters where it is called.... Thanks for your help, Jason Attachment FB_BROKE.zip (40 Downloads)
OUFAN75 Posts: 21 Rating: (1)
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6/22/2012 4:32 PM	Rate (0)
hdhosseini Diamond Expert Joined: 1/28/2009 Last visit: 9/25/2023 Posts: 6822 Rating: (1349)	OUFAN75 Good Morning, I created my 5th FB in my project with one rung of logic and when I call it as the first block in OB1 download it, it is green on the EN but the ENO is red (See attachment). When I move the call to anywhere else as long as it's not called first, it works and both EN and ENO are green as they should be. I am scratching my head on this one on why it matters where it is called.... Thanks for your help, Jason Hello OUFAN75, Attachment explain a bit your case with reconstructed case.I manipulate BR with "#br_manual" input parameter. [code] CLR A #in1 A #in2 = #aus A #br_manual SAVE [/code] Hope this helps Best regards Hamid Hosseini Attachment BR.zip (29 Downloads)
	Last edited by: hdhosseini at: 05/30/2019 23:10:24 Demo Channel on Youtube
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6/22/2012 5:02 PM	Rate (0)
OUFAN75 Posts: 21 Rating: (1)	Thanks for the video, but I am not following what the fix is. I do not have input parameters to my FB, it is just a called block. It looks like #br_manual is not assigned to anything in your block example and when you force the input on the block works but when you turn it off it doesn't. Please explain why this is happening. Thanks, Jason
OUFAN75 Posts: 21 Rating: (1)
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6/22/2012 6:33 PM	Rate (0)
0_Einstein Diamond Member Joined: 7/7/2010 Last visit: 9/27/2023 Posts: 13736 Rating: (2242)	OUFAN75 Thanks for the video, but I am not following what the fix is. I do not have input parameters to my FB, it is just a called block. It looks like #br_manual is not assigned to anything in your block example and when you force the input on the block works but when you turn it off it doesn't. Please explain why this is happening. Thanks, Jason Something _inside_ your FB is not set up properly when it is the first FB. Once another FB is called, the system now sets something that makes your problem FB happy. If you put all your tags usedin the FB as external inputs / outputs, you should be able to find the problem more quickly. Is there any tag used inside the FB that is changed by other FBs/FCs? Maybe a conversion is invalid without a value placed there by another FB/FC being called. I have seen similar problems with Siemens controls and it is more difficult to figure out because the code probably works just fine if you put it in the OB in place of calling the FB. The best advice anyone ever gave me to troubleshoot problems like this is to think like a PLC. It has no idea what you want to do, only what you told it to try to do.
	science guy
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6/22/2012 6:37 PM	Rate (0)
fritz Diamond Expert Joined: 10/7/2005 Last visit: 9/29/2023 Posts: 2989 Rating: (1034)	Hello OUFAN75 have alook at the following two threads,they'll hopefully contain the answers to your questions: Online Laddder - Dashed FB call Regarding the BR bit
	Cheers fritz The advice and opinion given in this thread is that of the author and does not necessarily reflect the views of I S Systems Pty Limited. To find out how I S Systems can help you with your automation needs please visit www.issystems.com.au.
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This contribution was helpful to 3 thankful Users hdhosseini 0_Einstein OUFAN75

6/22/2012 6:40 PM	Rate (0)
hdhosseini Diamond Expert Joined: 1/28/2009 Last visit: 9/25/2023 Posts: 6822 Rating: (1349)	OUFAN75 Thanks for the video, but I am not following what the fix is. I do not have input parameters to my FB, it is just a called block. It looks like #br_manual is not assigned to anything in your block example and when you force the input on the block works but when you turn it off it doesn't. Please explain why this is happening. Thanks, Jason Hello again, All you needed provided in the attachment.But, I think some complementary explanation is necessary! 1-BR is one of the status bits in CPU and used to implement EN/ENO mechanism.There are some useful posts in the forum you can search for.It is used as an indication for user of a function or a function block that execution of that done without any error in CPU.It is also applicable for System functions.Normally BR is set to "TRUE" in the beginning of a block and It is important for developer of a function to reset it in case of any error such as range violation in calculation, illegal floating point number,illegal input for arithmetic functions and ... . 2-So, in your case, As we can not see what you have done in your FB, I guess you never set "BR" and it is "FALSE" when function execution ends and you face the frightening red line.Simply, to avoid that, at least add following codes in your FB. [code] SET SAVE [/code] Thank you "fritz" for providing all related topics.I clustered all in the following TAG: Cases on BR-EN/ENO Mechanism Best regards Hamid Hosseini
	Last edited by: hdhosseini at: 6/22/2012 6:48 PM Last edited by: hdhosseini at: 05/30/2019 23:10:47 Demo Channel on Youtube
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This contribution was helpful to 3 thankful Users fritz 0_Einstein OUFAN75

6/22/2012 7:32 PM	Rate (0)
OUFAN75 Posts: 21 Rating: (1)	Thank you gentlemen for the detailed explanation
OUFAN75 Posts: 21 Rating: (1)
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