<P>I have two 450 processors networked to one scan node as below:</P>

<PRE>

PLC A PLC B
___ ___
I I I I
I___I I___I
I I
5 Ohm I I 5 Ohm T
[-----------------------------------------------]
BNC Network I
_I_
I I
I___I
SCADA

</PRE>
<P>I have been losing communication with PLC B while communication with PLC A is still healthy. I havetried checking the SCADA (FIX32 from Intellution - a rather old version I know...) and all the cables. There is no sign of damage on the cards and cables. To reset communications, I have to reset the whole system. What am I missing?</P>

 

bnc should be 50ohm terminators not 5 ohm that might be your problem but if thats a typing error then discard this reply

 

Thanks for the solution...

I eventually got it sorted out (can't remember how) but final solution was to upgrade to a newer PLC and SCADA system...