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Redundant Overview
Diagnostics
Revision 9
900 Control Station User Guide
49
May 2014
Item
Status
Possible Cause
Controller Action
What to do
I/O COMM ERROR
ON RESERVE
Reserve CPU is unable
to communicate with
one or more of the I/O
racks.
The lead controller
will continue to
control the process.
Failover to the
reserve is still
possible if a
subsequent failure
renders the current
lead less capable
than the reserve.
Verify all cabling between the
reserve CPU and the scanners.
Replace any Ethernet switches
between the reserve CPU and
the I/O rack(s).
Replace the reserve CPU
Replace the scanner CPU
Contact Honeywell service
DATABASE NOT
SYNCHRONIZED
Hardware failure on the
reserve CPU
Hardware failure on the
lead CPU
Hardware failure on the
CPU rack backplane
The lead controller
will continue to
control the process,
but failover is not
possible.
Replace the reserve CPU
Replace the lead CPU
Replace the CPU rack backplane
Contact Honeywell service
INVALID CONFIG.
Neither CPU has a valid
configuration database
An empty database
is created.
Download the desired
configuration file and perform a
cold start.
FIRMWARE
VERSION
MISMATCH
The reserve controller
does not have the same
version of controller
firmware installed
The lead controller
will continue to
control the process,
but failover is not
possible.
Upgrade the CPU firmware so
both the lead and reserve have
the same version.
CONTROLLER
STATUS
GOOD
N/A
N/A
N/A
FORCED OUTPUT A block has an output
that is forced.
None
Remove force on block output..
INVALID CONFIG.
A configuration that
exceeds the loop
capacity of the controller
was downloaded or an
invalid configuration
exists.
An empty database
is created.
Download a valid configuration.
SWITCH FAULT
RMS switch is indicating
an invalid position
The controller will
continue to operate
with a bad RSM.
Automatic failover is
still possible if
required.
Replace RSM
NO MASTER
PORT
The controller
configuration contains at
least on Modbus slave
block, but Serial Port S1
is not set up as a
Modbus Master port.
The controller is not
scanning the
Modbus slave
devices.
Select Modbus Master or
Modbus Master Advanced
protocol for either the RS-232 or
RS-485 port.