Honeywell HC900 - Page 198

184 HC900 Process & Safety Controller User and Installation Manual Revision 6
21 April 2017
Number
of
Strobes
Possible Cause
Scanner Action
User Action
2
The scanner has no configuration
data because it is unable to
communicate to the controller
CPU.
Possible causes include:
1. Scanner address switches are
not correctly set.
2. C75 only: The C75 I/O port is
connected to the wrong
Scanner 2 I/O port.
3. If a switch is used, there may
be a problem with it.
4. Cables are defective or are not
properly shielded.
5. Controller CPU is not powered.
6. Controller CPU and Scanner
firmware versions are
incompatible.
7. Defective Controller CPU,
Scanner, power supply, or rack.
Modules are not scanned and the outputs are
either at failsafe or in the power-down state. If
communication was lost while the modules
were being scanned, then the module outputs
are in their failsafe state. If communication
was never established to the Scanner, then
the module outputs are in the power-off state.
1. Verify that the address
switches on the scanner are
set correctly.
2. C75 only: Verify that the CPU
A cable is connected to the A
port, and the CPU B cable is
connected to the B port on the
Scanner 2.
3. If a switch is used, check that
all cables are properly
connected to the switch,
proper crossover cables are
used, that the switch is
powered, and it supports 100
Base-T.
4. Check cable shielding for
proper grounding and noise
immunity.
5. Make sure the cables have
the correct pinout.
6. Cycle power to the Scanner.
7. Cycle power to the switch.
8. Cycle power to the controller
CPU.
9. Replace the expansion rack’s
scanner module.
10. Ensure that the Scanner and
Controller CPU software
versions are compatible. If
not, perform a firmware
upgrade.
11. Replace the expansion rack’s
power supply.
12. Replace the expansion rack.
13. Replace the main CPU.
3
One of the following
microprocessor exceptions
occurred:
 Watchdog timer timeout
 Address error
 Prefetch error
 Data abort error
 Software interrupt
 Undefined instruction error
Scanner restarts. The main CPU detects that
the Scanner restarted, and places the
Scanner back into the scan mode.
Cycling power to the scanner will
clear the diagnostic.
If the problem reoccurs, try the
following:
1. Ensure the system is properly
grounded.
2. Ensure the system is properly
isolated from external noise
sources.
3. Upgrade scanner firmware
4. Replace scanner module
5. Contact Honeywell Personnel.
3
One of the exception vectors
located in RAM became corrupted.
The vector is restored to the proper value and
the Scanner continues to operate normally.
4
Flash failed to burn properly when
the firmware was being upgraded.
The boot code is the only software running.
This software waits for a request to burn the
flash. It does no scanning of modules. Module
outputs remain in their off state.
Perform a code download.