Hi Pros
I have multi system project each having its own power supply, I use independent tracking bench top power supply for other systems. some of the units have PC power supply, all signals connected to other systems are optoisolated. all cables sheilded, everything is EMI and noise protected, but i'm getting noise on my signals mostly from the system that has a pc power supply. My RS-232 cable was cozing problems when i connect it to isolated RS-232 connector, I had to remove the RS_232 sheild from touching the case of the PC for the problem to be removed but there is still problem with RS-232 coms.
All PCBs are perfect and cased adequately, all systems work perfectly when tested alone.
I dont know what the problem is, do u have any ideas?
Could it be earth problem, should i remove the earth connection of each power supply?
Thanx
Mahmood