Honeywell HC900 Benutzerhandbuch

Diagnostics and Troubleshooting - User Interface 

Revision 5 

  HC900 Hybrid Controller Installation and User Guide 

135 

9/03  

The scanner uses its LED to communicate diagnostic information. These diagnostics are a subset of the main CPU’s 
and are listed below. 

Diagnostic 
Condition 

Number 
of 
Strobes  

Possible Cause 

Scanner Action User 

Action 

Ram Failure 

1 

RAM failed on power-up. 

Executes an infinite 
loop that toggles the 
LED. 
Communications and 
module scanning are 
disabled. 

1. Cycle power 

2. Replace scanner 

3. Replace rack

 

Rom Failure 

1 

ROM failed on power-up. 

Executes an infinite 
loop that toggles the 
LED. 
Communications and 
module scanning are 
disabled. 

1. Cycle power 

2. Replace scanner 

3. Replace rack

 

Invalid 
configuration 

2 

The scanner has not been 
configured by the main CPU. 

Does no scanning of 
modules. Modules 
remain in their failsafe 
state. 

1. Verify that the jumpers on the 

scanner are setup for the 
correct rack address. 

2. If a hub is used, check that all 

cables are properly connected 
to the hub, proper crossover 
cables are used, and that hub 
is powered. 

3. Cycle power to the rack. 

4. Cycle power to the hub. 

5. Replace the expansion 

rack’s(C50 CPU only) power 
supply. 

6. Replace the expansion rack. 

7. Replace the main CPU. 

8. Replace the expansion rack’s 

scanner board.