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init bit

Created by: hefeng_05 at: 4/29/2009 8:21 AM (4 Replies)

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4/29/2009 8:21 AM	Rate (0)
hefeng_05 Posts: 60 Rating: (2)	Dear all who can tell me how can i write program in OB100 to make the bit is true when the CPU is warm start,and when the cpu is running the bit is false ?
hefeng_05 Posts: 60 Rating: (2)
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4/29/2009 8:45 AM	Rate (0)
Wüstenräuber Gold Member Joined: 10/3/2008 Last visit: 6/7/2023 Posts: 938 Rating: (120)	Hi, I would say, that you have to set the bit in OB100 and reset the bit in OB1 (always). But why you want to do this? If the CPU is restarted then the bit is set, but after OB100 the OB1 is called and the bit is reset immediately.What do you want to do with the bit? Wüstenräuber

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4/29/2009 6:14 PM	Rate (0)
Denilson Pegaia Platinum Member Joined: 9/23/2005 Last visit: 6/7/2023 Posts: 4184 Rating: (1342)	Hi, tip: The OB1 has many intern variable (TEMP). One is specialy interesting for this case: OB1_SCAN_1BYTE B#16#01: completion of a warm restart B#16#02: completion of a hot restart B#16#03: completion of the main cycle B#16#04: completion of a cold restart B#16#05: first OB1 cycle of the new master CPU after master-reserve switchover and STOP of the previous master
	Denilson Pegaia Siemens Industry Sector Technical Support
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4/30/2009 9:47 AM	Rate (0)
hefeng_05 Posts: 60 Rating: (2)	Dear all I want to use this bit to init my PID control .I used FB41(PID) in FUNCTION BLOCK and used muti instance . So i need one bit to init my PID controler when the cpu in warm restart. and the function block was called in OB35 does anybody who have a good way to deal with the bit of PID init.??? regards! ERIC
hefeng_05 Posts: 60 Rating: (2)
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4/30/2009 10:58 AM	Rate (0)
uel123 Gold Member Joined: 1/29/2006 Last visit: 5/28/2023 Posts: 438 Rating: (63)	hefeng_05 Dear all ... So i need one bit to init my PID controler when the cpu in warm restart. and the function block was called in OB35 does anybody who have a good way to deal with the bit of PID init.??? .... Hey, Eric! What kind of initialisation of your PID do you want to perform? Is it COM_RST (complete reset of PID) or I_ITL_ON (INITIALIZATION OF THE INTEGRAL ACTION ON)? The use of sudden actions in PID controll (like complete reset) may result in sudden changes of manipulated value. You must see, what effect will this have on your controlled system ! If you really want to perform a reset of PID (any kind,...) after restart of CPU, i propose a following method: - in OB100, set one memory bit (f.e. M100.0) - in OB35, test the status of this bit (M100.0). If bit is set, perform a PID reset and then reset your memory bit (M100.0) have fun! uel123

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