Honeywell 900U02-0100 - Page 213

Revision 10 ControlEdge HC900 Process & Safety Controller User and Installation Manual 199
May 2019
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.