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Old November 27th, 2021, 01:11 PM   #1
matatata
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E300 OL relay generating data while DCed

Im using studio 5000, in my software, Im using E300 overload protection relay to control a motor.



Studio 5000 Version 32.12
E300 Version 7


While controlling motor all seems to be ok, but while we were testing what would happen if we lose communication / power to E300 strange things seems to happen.


Some inputs of this datablock - AB:E300:I:3 - get written even without the communication with E300 relay(communication loss is instantaneous)


I tried to delete all instances where I m writting in this datablock and it still gets written. why?
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Old December 1st, 2021, 12:48 PM   #2
matatata
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Old December 1st, 2021, 08:31 PM   #3
Ken Roach
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What exact sub-elements of the Input tag "get written" ?

Do the values actually *change* and update ?

It is normal for the Input data to remain the last state from before the communications loss. A-B devices typically allow you to monitor the connection to be sure the data is valid, rather than implying there's something wrong by setting all the values to zero or another out-of-range value.

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>delete all instances where I'm writing in this datablock
That's an Input tag, which will be automatically updated by the I/O connection. You should not have any logic or HMI that "writes" to any element of that tag.
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Old December 1st, 2021, 09:12 PM   #4
matatata
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Quote:
Originally Posted by Ken Roach View Post
What exact sub-elements of the Input tag "get written" ?


I've only noticed that one that Im using like ready / average current and some other



Do the values actually *change* and update ?


Bool values go from 0 to 1, average current goes from 0 to some value(could be the last value before disconnecting)


It is normal for the Input data to remain the last state from before the communications loss. A-B devices typically allow you to monitor the connection to be sure the data is valid, rather than implying there's something wrong by setting all the values to zero or another out-of-range value.


Ok, I was checking connection state by using gsv block and if the communication isnt good, I would just copy empty block to this one, and somehow, values kept changing. Even where there is a no chance of communication(only ethernet cable pulled out)



That's an Input tag, which will be automatically updated by the I/O connection. You should not have any logic or HMI that "writes" to any element of that tag.


I never had this problem or similar problems just to set these values to zero if i lose communication with that certain device, now im using a buffer and it solved the problem but still... i would like to know why it happens.

answers are in black
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Old December 1st, 2021, 10:00 PM   #5
Ken Roach
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Never write values to an Input tag.

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>if the communication isnt good, I would just copy empty block to this one, and somehow, values kept changing.
I think that the values *appear* to be changing because your logic is competing with the I/O connection automatic data transfer.

Use the value of the GSV EntryStatus, divided by 4096, to determine if the connection is running. 4= Running, anything else is a broken or re-establishing connection.
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Old December 2nd, 2021, 09:32 AM   #6
matatata
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Quote:
Originally Posted by Ken Roach View Post
I think that the values *appear* to be changing because your logic is competing with the I/O connection automatic data transfer.

Use the value of the GSV EntryStatus, divided by 4096, to determine if the connection is running. 4= Running, anything else is a broken or re-establishing connection.

I would understand that it would be competing but, there is no connection, I'm not supposed to get this data, I only write in it when there is no connection


and that there is no connection i check with gsv, example in the picture

https://imgur.com/uJ2PYGD
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