10. C300 Controller Troubleshooting 
10.4. Fixing common problems 
Series 8 C300 Controller User's Guide 
Honeywell 
Secondary IOTA is defective. 
Replace the Secondary IOTA that initiated switchover when fault was 
detected. Refer to the section C300 Controller module and IOTA  
replacement for details. 
 
If Secondary controller synchronizes after replacement, the removed 
IOTA is defective. Otherwise, proceed to Cause 3. 
Primary controller is defective. 
Replace the Primary controller. Refer to the section C300 Controller  
module and IOTA replacement for details. 
 
If you can command synchronization after replacement, the removed 
C300 Controller is defective. Otherwise, proceed to Cause 4. 
Primary IOTA is defective. 
Replace the primary IOTA. Refer to the section C300 Controller module  
and IOTA replacement for details. 
If the controller pair synchronizes after IOTA replacement, the removed 
IOTA is defective. Otherwise, proceed to Cause 5. 
There is a software problem. 
 
Duplicate Device Index setting 
The FTE subsystem detects duplicate Device Index settings in separate nodes. 
 
All nodes will stop tracking cable status for the detected duplicate Device 
Index value. Communications will continue and will not impact system 
performance until there is a cable fault. This fault will also be detected by 
the FTE System Management Tool. 
A duplicate Device Index could cause a duplicate IP Address. In most 
cases, the duplicate IP Address would be detected first and prevent the 
FTE diagnostic messages from being sent. 
Device Index switches on separate IOTA's are set to same value. 
Change Device Index switches setting on one of the IOTA's to a unique 
value. Refer to the section Reset Device Index and IP address of 
controller for more information.