FSBUS Noice/Interference HELP!?

[olealm]

Hi!

Sorry, my deutch is not what it used to be

I was connecting the FSBUS Interface modules of the 737NG
Pedestal today and was DISAPPOINTED! Have the COM board behind he
MIP and 2xDisplay/1xLED/1xKEY inside the pedestal box. The cable
connecting the pedestal interfaces with the COM board is shielded
and I have connected the shield to ground on the COM side. All
other cables are ordinary flat-cable.

Problem is that there seemes to be lots of electrical noice in
the "system" when I connect the bus cable (apporx. 1.8m long)
connecting the COM and the pedestal interface boards.. Have a
FSBUS Key interface in the MIP section also and that seemes to be
affected also (the test function shows lotsa quick signal
changes)! In addition the relatively short cables from
buttons/rotaries to the Key board (both are inside the pedestal
box) creates lots of "noice" also (in the test function for the
pedestal Key board typically turning any rotary will generate
on/off signals for all buttons in that row.

The Key Interfaces are CID 1 and 2.

All in all a big disappointment!!

Question is: Is there anything to do to fix this ??
What Interface solution are you guys using and have you had similar noice problems ?

Please dont tell me all the interface work/expences was in wain
and that I have to go for a different solution...