F71 - Devicenet network with powerflex

[Karim Halawa]

I have running devicenet network consist of 1796-SDN and 12 powerfexs 40 .
the problem is during the line operation F71 occurs occasionally on Powerflex screen NOT on the scanner .
And this not fixed for just one drive it is appears on all of them but not in same time .
I replaced the powerflexs , replaced the resistance , replaced the cabling but without hope .

The only solution i didn't go through is 1796-SDN replacement .
Are there any one help on replacement procedures ?

Could you please anyone help on this ???

 

[gclshortt]

http://www.plctalk.net/qanda/archive/index.php/t-30227.html

I would look at the above thread for the answer. Its probably a grounding issue with the drives.

Regards,

 

[Karim Halawa]

thanks gclshortt , Buti believe the problem on scanner itself , could you please let me know procedures for the scanner replacement ?

 

[Ken Roach]

Error code F71 on the PowerFlex 40 drive indicates "Net Loss".

Have you been able to observe the diagnostic LEDs on the 22-COMM-D modules themselves ?

Are you using a 22-COMM-D module in each PowerFlex drive, or are you using them in "Multi-Drive Mode" ?

I realize that you think you've done all the diligence you can on the network wiring, but intermittent F71 errors that only affect some of the drives are still almost certainly a problem with electrical noise on the network.