AS Interface node failure

blknight

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B

Join Date

Jul 2008

Location

SYDNEY

Posts

3

• Jul 6, 2008

• #1

Hi,



I have an issue with an ASI network were the last node keeps failing. The module connected is a FESTO VALVE which communicates with the PLC via an ASI bus.



I have replaced the ASI module and within 24 hours and it failed again. I checked the power supply to the ASI line, and this is a good constant 31VDC. The auxiliary supply to the module is a good constant 24VDC.



The strange thing is that this module is the only one effected, there is another similar Festo module at the beginning of the network which functions ok. The one that fails is on the very end of the line.



Is there a plug that can go on the end of the ASI cable to help filter any spikes?

 

kiwi sparky

Member

K

Join Date

Sep 2006

Location

Auckland

Posts

51

• Jul 7, 2008

• #2

How far is the node from the master?

Define Failing? What is happening to this node

Any other changes to this ASi network lately.

 

blknight

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OP

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Join Date

Jul 2008

Location

SYDNEY

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3

• Jul 8, 2008

• #3

Thanks for your prompt reply.



1 ASI run lengths would be no more than 20-30 meters

2. The module at the end dies, it has to be physically swapped over to a new one.

3. No changes were made this issue had been happening since day one.

 

504bloke

Lifetime Supporting Member

Join Date

Jan 2005

Location

Down South

Posts

2,721

• Jul 8, 2008

• #4

Earthing and static?

I had a customer with the same trouble on an asi valve, turned out to be build up of static, reason was the earth bonding which was there on installation had broken.
Renewed the earth and the problem went away.