Electrical noise on the carrier affects the communication between
Series 2 redundant serial cards and causes them to switch over. To correct this
issue:
Determine if there is any electrical noise near the carrier and,
if so, remove the noise source.
Flashing red LEDs and loss of communication between the card and
the carriers indicate the existence of noise. Noise can be caused by electrical
activity (such as welding), the use of devices (such as 2-way radios), or
natural causes (such as lightning), occurring close to the DeltaV installation.
Reset the serial cards by removing each card from the carrier and
then re-inserting it into its slot.
Open DeltaV Diagnostics (click
Start → DeltaV
Operator → Diagnostics).
For each card, right-click the card, and then select
Clear Saved Fault Information.