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SCL Rising Edge doesn't work?

Created by: RasmusAKEA at: 2/12/2014 7:09 AM (19 Replies)

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2/12/2014 7:09 AM	Rate (0)
RasmusAKEA Advanced Member Joined: 8/27/2013 Last visit: 3/15/2023 Posts: 36 Rating: (0)	Hello Folks. I'm trying to make a rising edge in SCL, accordint to different threads here at the forum. After reading a lot, the solution must be: IF Trigger AND NOT Trigger_OLD Then Count := Count +1; End_IF; Trigger_OLD := Trigger; But this doesn't count correct, i've made a corresponding trigger in LAD, to control, and seems like the SCL rising edge only works a few times... What can be wring? I'm counting pulses from a S0 output at an energy meter, the pulse should last for 40 ms, which should be more than enough to see the input.

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2/12/2014 7:24 AM	Rate (0)
hdhosseini Diamond Expert Joined: 1/28/2009 Last visit: 2/21/2023 Posts: 6794 Rating: (1341)	RasmusAKEA Hello Folks. I'm trying to make a rising edge in SCL, accordint to different threads here at the forum. After reading a lot, the solution must be: IF Trigger AND NOT Trigger_OLD Then Count := Count +1; End_IF; Trigger_OLD := Trigger; But this doesn't count correct, i've made a corresponding trigger in LAD, to control, and seems like the SCL rising edge only works a few times... What can be wring? I'm counting pulses from a S0 output at an energy meter, the pulse should last for 40 ms, which should be more than enough to see the input. Hello, You need a change like this: IF (Trigger =1) AND (Trigger_OLD =0 ) Then Count := Count +1; End_IF; Trigger_OLD := Trigger; Also, check this sample coming from HERE [code] ORGANIZATION_BLOCK OB1 TITLE = 'HELP_ON_SCL' // // Block Comment... // VERSION: '1.0' AUTHOR: HD NAME: H_SCL FAMILY: FORUM_E VAR_TEMP // Reserved info : ARRAY[0..19] OF BYTE; // Temporary Variables END_VAR // Statement //FLANK1:=0; // OUT:=0; IF START =1 THEN IF TWO =1 AND FLANK1 =0 THEN ZAHL:=ZAHL+1; END_IF; FLANK1:=TWO; IF (ZAHL >= 0) AND (ZAHL <2) THEN OUT:=1; ELSE OUT:=0; ; END_IF; IF ZAHL>5 THEN ZAHL:=0; END_IF; ELSE zahl:=0; flank1:=0; OUT:=0; ; END_IF; ; END_ORGANIZATION_BLOCK[/code] I hope it helps Hamid Hosseini
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2/12/2014 7:34 AM	Rate (0)
RasmusAKEA Advanced Member Joined: 8/27/2013 Last visit: 3/15/2023 Posts: 36 Rating: (0)	Thanks... But i can't see why the brackets should change the evaluation method? Could you please explain :) Yes i've seen that example, and also thought i've done it the same way :) Greetings :)

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2/12/2014 9:59 AM	Rate (0)
hdhosseini Diamond Expert Joined: 1/28/2009 Last visit: 2/21/2023 Posts: 6794 Rating: (1341)	RasmusAKEA Thanks... But i can't see why the brackets should change the evaluation method? Could you please explain :) Yes i've seen that example, and also thought i've done it the same way :) Greetings :) Hello, Just share an update.There is no obvious differences between my proposed SCL codes and yours.I am sure that the SCL compiler treats them the same way and the resulting machine codes are identical.There is magic hidden in those brackets and I just add them for more clarity.About the malfunction,I guess the pulse that is fed to your program doesn't last enough for proper execution of the program.I suggest using a hardware interrupt (if possible) or a cyclic interrupt with a resolution better than pulse coming from hardware. I hope it helps Hamid Hosseini
	Demo Channel on Youtube
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2/12/2014 10:39 AM	Rate (0)
RasmusAKEA Advanced Member Joined: 8/27/2013 Last visit: 3/15/2023 Posts: 36 Rating: (0)	Thanks a lot :) I like your qutoe: "There's magic hidden in theese brackets" :) I will try and make it interrupt based instead :)

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2/12/2014 10:42 AM	Rate (1)
Aret Posts: 2348 Rating: (259)	I guess you put your Trigger in TEMP area, so it can be cleared between calls - please check if it lies in STAT, M or DB areas.
Aret Posts: 2348 Rating: (259)
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This contribution was helpful to 1 thankful Users Adcsi

2/12/2014 10:56 AM	Rate (0)
RasmusAKEA Advanced Member Joined: 8/27/2013 Last visit: 3/15/2023 Posts: 36 Rating: (0)	@Aret: I've did that first, but changed it to be in STAT Var in my FB :)

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2/12/2014 11:02 AM	Rate (0)
Aret Posts: 2348 Rating: (259)	Hmmm, can you upload whole project here? I usually work with edges in SCL without any problems.
Aret Posts: 2348 Rating: (259)
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2/17/2014 7:40 AM	Rate (0)
RasmusAKEA Advanced Member Joined: 8/27/2013 Last visit: 3/15/2023 Posts: 36 Rating: (0)	Hello. Did you find anything in the project that caused the Rising Edge to fail?

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2/17/2014 3:59 PM	Rate (0)
hdhosseini Diamond Expert Joined: 1/28/2009 Last visit: 2/21/2023 Posts: 6794 Rating: (1341)	RasmusAKEA Hello. Did you find anything in the project that caused the Rising Edge to fail? Hello again , I have read all posts in the thread thoroughly, evenmine , while seeking for an attachment and for sure I missed that in absent period last week. I hope you can upload it again for our evaluation! Many regards, Hamid Hosseini
	Demo Channel on Youtube
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