Table 29 - Scanner Led Diagnostics - Honeywell HC900 Installation And User Manual

Diagnostics and Troubleshooting - Scanner indicators
Scanner Diagnostic LED Indication
The scanner uses its LED to communicate diagnostic information. These diagnostics are a subset of the main CPU's
and are listed below.
Number Possible Cause
of
Strobes
1 RAM or ROM failed diagnostics on
power-up.
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.
172
Table 29 – Scanner LED Diagnostics
Scanner Action
Executes an infinite loop that toggles the LED.
Communications and module scanning are
disabled. Module outputs are in the power-off
state -- DO outputs are off, and AO outputs
are at zero milliamps.
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.
HC900 Process Controller Installation and User Guide
User Action
1. Cycle power
2. Replace scanner
3. Replace rack
4. Check grounding
5. Ensure system is properly
isolated from noise
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.
Revision 19
06/14