176 HC900 Process & Safety Controller User and Installation Manual Revision 6
21 April 2017
Controller Status LED Diagnostic indicators
When the Controller has a flashing amber status LED after power-up a critical, power-on-self-test, error has
occurred that requires controller module replacement. When the Controller Status LED (Figure 89 on page 174, item
1) is flashing red, consult Table 27.
Hazardous voltages exist in the equipment enclosure.
Identify and avoid contact with voltage sources.
Disconnect power before servicing. (More than one switch may be required to disconnect all power.)
Failure to comply with these instructions could result in death or serious injury.
Table 27 – Controller Status LED Diagnostics
Lead and/or Reserve Controller
Action(s)
HCDesigner/HC
Utilities Indication
RAM or ROM failed on
power-up.
Executes an infinite loop that toggles
the LED. Communications and
control are disabled.
2. Replace CPU
3. Replace power supply
4. Replace rack
5. Check grounding
6. Ensure system is properly isolated
from noise
Not available
because the C75
communication
ports are disabled.
Not available
because the C75
communication
ports are disabled.
At least one function
block has an output
that is forced.
The block’s output(s) is/are forced to
the value(s) specified.
If it is not desirable to have forced
block outputs, use HCDesigner to
locate and remove the forced outputs.
See SYSTEM in
the “Controller
Diagnostics
Overview” display.
See System
Diagnostics in
the “Diagnostic
Overview” dialog
box.
The RAM and FLASH
copies of the
configuration database
were corrupted and
are now set to a valid
empty database.
Usually this is a result
of a firmware upgrade.
An empty database is created, and
the lead and reserve will not
synchronize. The reserve’s RSM
LED is flashing to indicate it’s not
synchronized with the lead.
Use HCDesigner, HCUtilities, or OI to
download a valid configuration.
One of the following
RSM failures was
detected:
1. The RSM module is
not installed.
2. The RSM switch
position is invalid.
3. The lead and
reserve switch
positions do not
agree.
The lead uses its own switch
reading and dictates to the reserve
what the mode is. If the lead’s switch
position is invalid, then the lead uses
the last good known position prior to
the failure.
If failover occurs, the new lead will
assume the mode prior to failover
until a good switch reading is
acquired.
If after the power is cycled to both
the lead and reserve, and the lead is
unable to acquire a valid switch
position, the system will default to
the run-program mode of operation.
This diagnostic will cause the
HWOK pins of the analog and fast
logic “System Monitor” blocks
(AYSY and FSYS) to be turned off.
1. Install RSM if none present. NOTE:
WHEN PLUGGING IN THE RSM
INTO A LIVE UNIT, YOU MUST
MAKE SURE THE SWITCH IS IN
THE PROPER STATE PRIOR TO
INSERTION.
2. If the key is installed in the RSM,
remove it to make sure the switch is
seated properly. If the key does not
pull out, turn it slightly to the proper
position until it can be removed.
3. Replace the RSM
4. Replace reserve CPU
5. Replace lead CPU
6. Replace rack
To Next Page
Loading...
