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S7 300 REDUNDANCY PROBLEM

Created by: Amol V at: 3/29/2014 8:43 AM (3 Replies)

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3/29/2014 8:43 AM	Rate (0)
Amol V Experienced Member Joined: 9/21/2013 Last visit: 6/17/2024 Posts: 66 Rating: (1)	Dear all, I am having problem with S7-300 redundancy my redundancy is working for DI/DO/AI/AO but problem came when i am modifying value of memory word in one PLC but i am confused that at what time my same memory word is updated in second PLC means memory word of second PLC is upadated instantly or at the time of changeover. My memory address is not get updated at the time of changeover or instanly. I reffered the manual but i don't found anything different if anybody have any idea please tell me.

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3/30/2014 7:32 AM	Rate (0)
S7 AUTOMAN Posts: 515 Rating: (56)	hi, what i usually does is whenever you are doing some modifications/changes, do it in the standby/secondary CPU first and then download it to the same and then you do that to the Main/primary CPU. I guess this is even recommended in the Software redundancy manual as well, i dont remeber it exactly
S7 AUTOMAN Posts: 515 Rating: (56)
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3/30/2014 11:03 AM	Rate (0)
Navnag Platinum Member Joined: 11/21/2007 Last visit: 8/12/2024 Posts: 2325 Rating: (308)	Amol V Dear all, I am having problem with S7-300 redundancy my redundancy is working for DI/DO/AI/AO but problem came when i am modifying value of memory word in one PLC but i am confused that at what time my same memory word is updated in second PLC means memory word of second PLC is upadated instantly or at the time of changeover. My memory address is not get updated at the time of changeover or instanly. I reffered the manual but i don't found anything different if anybody have any idea please tell me. Hello Amol V You can specify Which Flag Bytes will be updated from the Master to standby bythe parameters MB_NO and MB_LEN of FB 100 of Software Redundancy. e.g. if you set MB_NO = 100 and MB_LEN = 20 then Flag bytes from MB 100 to MB 119 will be continuously updated from the Master to the Standby CPU. ( At what speed ? ... it not clear .. Speed basically depends on the total volume of data specified to be updated from the Master to Standby CPU including DBs, MBs etc ) Any other Flag bytes areNOT updated from the Master to the Slave CPU any time( Including Changeover ). Hope this helps Cheers Navnag
	There is no such thing as the last bug in a program There are no stubborn bugs, There are only stubborn Debuggers.
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3/31/2014 6:08 AM	Rate (0)
Amol V Experienced Member Joined: 9/21/2013 Last visit: 6/17/2024 Posts: 66 Rating: (1)	Thank you for the reply but i solved the issue after reprogramming the plc.

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This contribution was helpful to 2 thankful Users Navnag S7 AUTOMAN

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