Troubleshooting Module Faults Second Response - Honeywell Touchpoint Pro Technical Handbook

POTENTIAL OPERATING ISSUES

19.3 Troubleshooting Module Faults Second Response

If the first response fails, Ring operation may be restored by physically removing a faulty module. However, the system will
continue to report the module and its channel as faults (unless the channels are inhibited).
In the unlikely event of multiple module failure, any modules between the faulty modules will be hidden from the controller. If
this happens you can remove faulty modules from the backplane to restore communication to the remaining modules. (It is
not necessary to remove backplane power when disconnecting and replacing modules, but troubleshooting and repairs
should only be done by qualified persons).
Removing a module will render its channels inoperative, so you must make alternative safety arrangements until the
19.3.1 Ring Wiring Faults
Ring wiring faults will typically be reported by the system during initial commissioning (due to faulty module insertion or faulty
wiring etc.), or as a result of physical damage or disturbance in the ring bus possibly caused during module removal or
fitting.
19.3.2 RCM Faults
Where a fault is reported between the CCB and the first or the last module, the system cannot identify whether the error is
between the CCB and the RCM, or between the RCM and the module, or in the RCM itself. In practice faults are most likely
to be in the wiring between TB2/TB3 and the RCM(s).
19.3.3 Ring Terminals
Ring terminals are defined as (Ring) A-in, A-out, B-in and B-out (see Ch. 5.4.1 Ring Wiring for further details).
19.3.4 Ring Faults on Initial Commissioning
At initial commissioning the system will typically report a ring fault or ring oscillation if a fault is already present. If this
happens:

For new installations, visually check that all module LEDs are green and flashing.

Visually check the two ring LEDs on each RCM. They should be flashing alternately at the same rate. On most
systems the corresponding CCB LEDs may be checked through a hole at the left edge of the controller's back cover.

Visually check that the power LED on each module is illuminated. If not illuminated, check that backplane power is
present and that the module is correctly fitted on the backplane connector.

Initialise the ring to ensure that all modules are responding and/or to localise the faulty area. The system will list all
detected modules in the System Setup screen.

Check that each module is shown, and that the order is correct. (Uncommissioned modules will be listed in the order
that they are connected – following the order of the A ring – but the order will change when they are commissioned.)

Check for obvious wiring faults and check that screw terminals are correctly tightened.

If ring oscillation is observed, check for correct circuit wiring, e.g. that B-out isn't incorrectly connected to RCM B-in, or
that wiring isn't crossed or shorted between the A and B rings.

Try removing most of the modules from the backplane to help distinguish between Wiring and Module faults – a
backplane with only an RCM fitted will operate over short wiring distances but at least one IO module must be fitted to
each backplane for normal operation over longer distance.
Part. No. 2400M2501_6
WARNING
module is replaced and its channels reconfigured and recalibrated.
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